Doctor (Doctor Who)

Doctor Who character
The eleven faces of the Doctor in chronological order. Left to right from top row; William Hartnell, Patrick Troughton, Jon Pertwee, Tom Baker, Peter Davison, Colin Baker, Sylvester McCoy, Paul McGann, Christopher Eccleston, David Tennant and Matt Smith. Click a picture for main article.
The Doctor
Species	Time Lord
Home planet	Gallifrey
First appearance	An Unearthly Child
Portrayed by	William Hartnell (1963–1966) Patrick Troughton (1966–1969) Jon Pertwee (1970–1974) Tom Baker (1974–1981) Peter Davison (1982–1984) Colin Baker (1984–1986) Sylvester McCoy (1987–1989, 1996) Paul McGann (1996) Christopher Eccleston (2005) David Tennant (2005–2010) Matt Smith (2010–present)

The Doctor is a title character and the protagonist of the long-running BBC television science fiction series Doctor Who, and has also featured in two cinema feature films and one made-for-television movie, as well as a vast range of spin-off novels, audio dramas and comic strips connected to the series.

To date, eleven actors have played the role in the television series, with continuity being maintained by the ability of the character's species to regenerate. Several other actors have played the character on stage and film, in audio dramas, and in occasional special episodes of the series. The character's enduring popularity led the Daily Telegraph to dub him "Britain's favourite alien". The Doctor, in his eleventh incarnation, is currently played by Matt Smith, who took on the role in January 2010 and became the first Doctor to be nominated for a BAFTA Award for Best Actor in a Leading Role in 2011.

Background

The Doctor is a Time Lord, an extraterrestrial from the planet Gallifrey, who travels through time and space in an internally vast time machine called the TARDIS (Time And Relative Dimension(s) In Space) which appears relatively small when seen from the outside, but is in fact very large on the inside.

The Doctor explores the universe at random, using his extensive knowledge of science, technology and history to avert whatever crisis he encounters. The imprecise nature of his travels is initially attributed to the age and unreliability of the TARDIS's navigation system. However, the 1969 serial The War Games reveals that the Doctor actually stole the TARDIS, and subsequent stories such as " Planet of the Dead", " The Big Bang" and " The Doctor's Wife" have incorporated this. Additionally, it has been mentioned that the TARDIS is meant to be piloted by six Time Lords, rather than just one. He was presumably unfamiliar with its systems but was able to operate it correctly until his exile when the Time Lords wiped it from his memory. The Doctor initially had the manual for operating the TARDIS but destroyed it (by throwing it into a supernova) because he disagreed with it. After his trial and exile to twentieth century Earth, the Doctor still visits other planets on missions from the Time Lords who pilot the TARDIS to precise locations for him.

After his exile is lifted, the Doctor returns to his travels and demonstrates the ability to reach a destination of his own choosing more often than not. In the 2011 episode "The Doctor's Wife", the Doctor tells the TARDIS (whose matrix, or soul, was temporarily transferred to the character Idris) that she has never been very reliable in taking him where he wanted to go. The TARDIS explains that she always took the Doctor where he needed to be. In " Journey's End", the Doctor states that the reason for the previous bumpy navigation was that the TARDIS is meant to have six pilots, but in " The Time of Angels", River Song demonstrates superior piloting skills and says the Doctor pilots the TARDIS "with the brakes on" (hence the classic noise), though she could have been teasing him. The Doctor generally travels with one or more companions. Most of these make a conscious decision to travel with him, but others, especially early in the series, are accidental passengers or kidnap victims.

The Doctor's childhood

The Doctor's childhood is described very little. The classic series often refers to his time at the academy and that he belongs to the Prydonian chapter of Time Lords, who are notoriously devious. His teachers included Borusa, who would eventually become President of the High Council, and other pupils included the Master and possibly the Rani. The Eighth Doctor, in the 1996 television movie, is the first to mention his parents or childhood before this, when he tells Grace Holloway that he remembers watching a meteorite shower from a grassy hill top in the company of his father.

During " The Girl in the Fireplace", Madame de Pompadour "saw" memories of his childhood during a telepathic exchange between the two and commented that it was "so lonely." When asked if he has a brother in " Smith and Jones", the Doctor simply replied "not anymore". In the same episode, he mentioned "playing with Röntgen blocks in the nursery." He was also once good friends with the Master.

In The Time Monster, the Doctor says he grew up in a house on the side of a mountain, and talks about a hermit who lived under a tree behind the house and inspired the Doctor when he was depressed. He is later reunited with this former mentor, now on Earth posing as the abbot K’anpo Rinpoche, in " Planet of the Spiders".

In the BBC novel The Nightmare of Black Island the Doctor stated his favourite childhood story was Moxx In Socks. In " Mission to Magnus", the Doctor tells how at the Academy he was bullied by another Time Lord named Anzor. In " Master", the Doctor tells how he killed a bully who tormented him and the Master. It's possible this could be Anzor as well.

In " The Sound of Drums" (2007), the Doctor describes a Time Lord Academy initiation ceremony where, at the age of eight, Time Lord children are made to look into the Untempered Schism, a gap in space and time where they could view the time vortex. Some are inspired, some go mad (as he suggests happened to his nemesis, the Master), and some run away. When asked to which group he belonged, he replied, "Oh, the ones that ran away—-I never stopped!"

In The End of Time, the Master describes his and the Doctor's experiences together, saying, "I had estates. Do you remember my father's land back home? Pastures of red grass, stretching far across the slopes of Mount Perdition. We used to run across those fields all days, calling up at the sky."

The most complete glimpses into the Doctor's childhood occurs in the Virgin New Adventures novel Lungbarrow; however, as with all non-televised Doctor Who media, the canonicity of this story is unclear. Lungbarrow portrays the Doctor as being one of 45 cousins grown from the House genetic loom as an adult. (In New Adventures continuity, the Time Lords are not capable of sexual reproduction and survive through genetic looms producing a quota of cousins.) The Head of the Family Ordinal General Quences knew that the Doctor had a special destiny and built him a robot tutor called Badger and planned the Doctor's eventual rise to the post of President. His fellow cousins resented the Doctor's position and he spent most of his childhood being bullied by his cousin Glospin and was equally brutally treated by the Housekeeper Satthralope. Eventually he rebelled against Quences's grand plans and was exiled from the family, stealing a TARDIS and leaving Gallifrey. This depiction of events is seemingly contradicted by "The Sound of Drums", showing the Master as a child. The BBC Books novel The Infinity Doctors, for example, states that the Doctor was born from the loom, but it adds that he was also the son of a Gallifreyan explorer and a human mother.

Family

References to the Doctor's family are rare in the series. During the first two seasons he travelled with his granddaughter, Susan Foreman, and as noted above he apparently once had a brother.

During his second incarnation when asked about his family, the Doctor says his memories of them are still alive when he wants them to be and otherwise they sleep in his mind ( The Tomb of the Cybermen). In The Time Monster, the third Doctor states that as a little boy he lived in a house perched halfway up a mountain. In The Curse of Fenric, when asked if he has any family, the Seventh Doctor replies that he does not know, indirectly hinting that an unspecified fate may have befallen them.

In " Fear Her", the Tenth Doctor mentions to Rose that he "was a dad once", but then quickly changes the subject; he makes the same admission to Donna in " The Doctor's Daughter" when she assumes that he has "Dad-shock". He later clarifies in the same episode that he had been a father but that was lost to him during the Time War. In " The Empty Child", Dr. Constantine says to him, "Before this war began, I was a father and a grandfather. Now I'm neither. But I'm still a doctor." The Doctor's reply is, "Yeah. I know the feeling." When asked by Amy Pond in " The Beast Below" if he is a parent, the Doctor simply changes the subject. When the Doctor gifts Amy and Rory's newborn daughter with an ancient bassinet in " A Good Man Goes to War", Amy again asks if he has children. The Doctor does not answer the question though he does tell Amy that the bassinet was his as a baby. In " Night Terrors", the Doctor attempts to help amuse a little boy by talking about fairy tales he used to enjoy and also uses his sonic screwdriver to make the boy's toys move. The Doctor mumbles that he is "a bit rusty at this."

He mentions his father in the 1996 Doctor Who telefilm, where he also indicates his mother was human (see "Continuity curiosities" below).

In " The Doctor's Daughter", the Doctor had his genetic information stolen and used to create a female soldier and comes to refer to the result, a young woman eventually named Jenny (played by Georgia Moffett, real world daughter of Peter Davison and wife of David Tennant), as his daughter; she in turn knows him as her father. At the end of the episode, she is killed, but later regenerates and steals a rocket, intending to become an adventurer like her father. It is unknown if she will ever return.

By the end of the series " Journey's End" a half-human Doctor is created from his severed hand, when the Tenth Doctor transfers his regeneration energy into the hand to prevent a full regeneration of his own body. Both Doctors share the same memories up until that point but the half-human Doctor also has elements of Donna Noble's personality and her DNA as a result of her touching the hand, causing the mass regeneration to occur. The "Meta-Crisis" Doctor has only one heart and cannot regenerate.

In the episode " Blink", the Doctor states that he never was good at weddings, especially his own. According to both his greeting speech to Ood Sigma in The End of Time and his breakdown to Dorium Maldovar in " The Wedding of River Song", sometime between " The Waters of Mars" and the beginning of The End of Time, the Doctor also married the former "Good Queen Bess". During his speech he states "Her nickname is no longer . . . " before being interrupted, and notes on the experience "That was a mistake." The possibility exists that the Doctor could just be having a laugh here; however, the story persisted, as her distant successor Liz Ten (" The Beast Below") comments, "And so much for the Virgin Queen, you bad, bad boy!" In " A Christmas Carol", the Doctor finds himself engaged to Marilyn Monroe but later claims the wedding did not take place in a legitimate chapel. When River Song shows up in " Time of Angels", Amy asks both the Doctor and River if they are married to each other. The Doctor initially says yes but that is in his future but her past while River's answer seems affirmative but ambiguous. In " The Big Bang", the Doctor asks River Song if she is married; she asks if he's asking and the Doctor says he is. Her answer leaves the Doctor puzzled, wondering if she had thought that he had proposed and if she had just accepted. She replies with another enigmatic, "Yes."

In The End of Time, a mysterious individual, referred to only in the credits as "The Woman", appears unexpectedly to Wilfred Mott throughout both episodes. She is later revealed to be a dissident Time Lady, who opposed the Time Lord High Council's plan to escape the Time War. When she reveals her face to the Doctor, his reaction indicates that he recognises her. Julie Gardner, in the episode's commentary, states that while some have speculated that the Time Lady is the Doctor's mother, neither she nor Russell T. Davies are willing to comment on her identity. When later asked by Wilfred who she was, the Doctor evades answering the question, making their connection unclear. In Doctor Who: The Writer's Tale – The Final Chapter, Russell T Davies states that he created the character to be the Doctor's mother and this is what actress Claire Bloom was told when she was cast.

In " The Wedding of River Song" the Doctor marries River Song, making her his wife. This also makes Amy Pond and Rory Williams his in-laws as well as both the Ponds and Williams' families now being related to him.

Spin-off family

In a number of spin-off material, a number of individuals related to the Doctor have made appearances which don't appear in the television series.

In the First and Second Doctor comics and annuals, the Doctor travelled with two of his grandchildren named John and Gillian.

In the novel Legacy of the Daleks, it is revealed that Susan and her husband David adopt three children who they name David Campbell Junior, Ian and Barbara; named after David himself, Ian Chesterton, and Barbara Wright respectively.

In the novel Father Time, the Eighth Doctor, during his hundred-year-long exile on Earth, found an orphaned Time Lord girl named Miranda whom he adopted and raised till she was 16. Later she returned to the Doctor along with her daughter Zezanne in the novel Sometime Never.... She was also the central character in a three-issue comic book series published by Comeuppance Comics in 2003. Author Lance Parkin, who devised the character, has hinted that her real father is actually a future incarnation of the Doctor which, if so, would make Zezanne the Doctor's biological granddaughter as well.

In the beginning

The character of the Doctor was created by the BBC's Head of Drama Sydney Newman. The first format document for the series that was to become Doctor Who – then provisionally titled The Troubleshooters – was written up in March 1963 by C. E. Webber, a BBC staff writer who had been brought in to help develop the project. Webber's document contained a main character described as "The maturer man, 35–40, with some 'character twist.'" However, Newman was not keen on this idea and – along with several other changes to Webber's initial format – created an alternative lead character named Dr Who, a crotchety older man piloting a stolen time machine, on the run from his own far future world. No written record of Newman's conveyance of these ideas – believed to have taken place in April 1963 – exists, and the character of Dr Who first begins appearing in existing documentation from May of that year.

The character was first portrayed by William Hartnell in 1963. At the programme's beginning, nothing at all is known of the Doctor: not even his name, the actual form of which remains a mystery. In the first serial, An Unearthly Child, two teachers from Coal Hill School in London, Barbara Wright and Ian Chesterton, become intrigued by one of their pupils, Susan Foreman, who exhibits high intelligence and unusually advanced knowledge. Trailing her to a junk yard at 76 Totter's Lane, they encounter a strange old man and hear Susan's voice coming from inside what appears to be a police box. Pushing their way inside, the two find that the exterior is actually camouflage for the dimensionally transcendental interior of the TARDIS. The old man, whom Susan calls "Grandfather", subsequently kidnaps Barbara and Ian to prevent them from telling anyone about the existence of the ship, taking them on an adventure in time and space. The first Doctor, says cultural scholar John Paul Green, "explicitly positioned the Doctor as grandfather to his companion Susan." He wore a long white wig and Edwardian costume, reflecting, Green says, a "definite sense of Englishness".

When, after three years, Hartnell left the series due to ill health, the role was handed over to respected character actor Patrick Troughton. To date, official television productions have depicted eleven distinct incarnations of the Doctor (following Hartnell's death in 1975, actor Richard Hurndall substituted in his role as the First Doctor in 1983's The Five Doctors, resulting in a technical total of twelve actors). Of those, the longest-lasting on-screen incarnation is the Fourth Doctor, as played by Tom Baker. Currently, the Eleventh Doctor is portrayed by Matt Smith.

Becoming "involved"

The Doctor is an adventurer and scientist with a strong moral sense. He usually solves problems with his wits rather than with force, and is more likely to wield a sonic screwdriver than a gun, although he has been seen to use weapons as a last resort. According to the alien villain Chedaki in the episode The Android Invasion, "his long association with libertarian causes" shows that "his entire history is one of opposition to conquest."

As a time traveller, the Doctor has been present at, or directly involved in, countless major historical events on the planet Earth and elsewhere—sometimes more than once. In the 2005 series premiere, " Rose", it is revealed that the Ninth Doctor was instrumental in preventing a family from boarding the Titanic prior to her fateful voyage. In " The End of the World", the Doctor recalls having been on board and surviving the Titanic's sinking to find himself "clinging to an iceberg". The Fourth Doctor also mentioned this event in Robot and The Invasion of Time, where he insists that the sinking was not his fault; the Seventh Doctor became involved in the sinking when tracking an alien entity in the novel The Left-Handed Hummingbird, but this may not be canonical.

Many historical figures on Earth have also encountered the Doctor. In City of Death it is revealed that the Doctor has met Leonardo da Vinci and William Shakespeare (whom he met again, later from his perspective but earlier from Shakespeare's, in " The Shakespeare Code" as well a younger Shakespeare who he saved in his Eighth incarnation in " The Time of the Daleks"), and that the first folio of the latter's Hamlet was transcribed by the Doctor himself (City of Death). He has also met a young H. G. Wells ( Timelash), Albert Einstein ( Time and the Rani), Mao Tse Tung (Referenced in The Mind of Evil), Richard the Lionheart ( The Crusade), Wyatt Earp ( The Gunfighters), and Marco Polo ( Marco Polo). More recently, the Doctor has shared adventures with Charles Dickens (" The Unquiet Dead"), Benjamin Franklin (Referenced to in " Smith and Jones"), Agatha Christie (" The Unicorn and the Wasp"), Queen Victoria (" Tooth and Claw"), Elizabeth I (" The Shakespeare Code" and an untelevised adventure between " The Waters of Mars" and The End of Time), Madame de Pompadour (" The Girl in the Fireplace"), Winston Churchill (" Victory of the Daleks", also appeared in the novels Players and The Shadow in the Glass, Shadow also seeing the Doctor meeting Adolf Hitler) and Vincent van Gogh (" Vincent and the Doctor"). A photograph seen in the 2005 series shows that the Ninth Doctor witnessed the death of US president John F. Kennedy. The Fourth Doctor explains in " The Ark in Space" that his signature scarf was knitted for him by Madame Nostradamus, while the Tenth Doctor in " Gridlock" says that Janis Joplin gave him his brown overcoat and in "Smith and Jones" he tells Martha Jones that the Suffragette leader Emmeline Pankhurst stole his laser spanner when they met. The Eleventh Doctor mentions in " The Time of Angels" that he is on Virginia Woolf's bowling team.

It is this penchant for becoming "involved" with the universe—in direct violation of official Time Lord policy—that has caused the Doctor to be labelled a renegade by the Time Lords. (His defence of his involvement, first made in The War Games, notes and maintains that while most of his fellow Time Lords have been content merely to observe the evil in the Universe, he has been actively fighting against it.) Most of the time, however, his actions are tolerated, especially given that he has saved not just Gallifrey but also the universe several times over. The Time Lords are also partial to sending him on missions when deniability or expendability is needed, implied to have begun after his capture during " The War Games"- see Season 6B- and being witnessed further in later stories, the Time Lords directing the Doctor and/or the TARDIS to specific locations in Colony in Space, The Curse of Peladon, The Mutants, Genesis of the Daleks, The Brain of Morbius, and Attack of the Cybermen. The Doctor's standing in Time Lord society has waxed and waned over the years, from being a hunted man to being appointed Lord President of the High Council. He does not assume the office for very long, fleeing Gallifrey after his appointment rather than accepting the limitations on his freedom that the role would place on him (" The Five Doctors"), and is eventually removed from it in his absence ( The Trial of a Time Lord).

Physiology

Although Time Lords resemble humans, their physiology differs in some key respects. For example, like other members of his race, the Doctor has two hearts (binary vascular system), a "respiratory bypass system" that allows him to go without air, an internal body temperature of 15–16 degrees Celsius (60 degrees Fahrenheit) and he occasionally exhibits a super-human level of stamina, and the ability to absorb, withstand, and expel large amounts of certain types of radiation (the Tenth Doctor stated they used to play with Röntgen bricks in the nursery, after absorbing the radiation from an x-ray of significantly magnified power). This ability would seem to have limitations which have yet to be fully explained, as he is harmed by radiation in The Daleks, Planet of the Spiders, and The End of Time. Additionally, he has withstood exposure to electricity deadly enough to kill a human with minimal damage ( Terror of the Zygons, Genesis of the Daleks, Aliens of London, The Christmas Invasion, Evolution of the Daleks, spin-off audio Spare Parts). Certain stories also imply that he is somewhat resistant to cold temperatures. To counter extreme trauma, such as exposure to the poisonous fungus in The Seeds of Death and after being shot in Spearhead from Space, he can go into a self-induced coma until he recovers.

Additionally, he has shown a resistance to temporal effects and has demonstrated some telepathic ability, both the ability to mentally connect to other incarnations of himself he encountered ( The Five Doctors), and an ability to enter into the memories of other individuals, similar to the Vulcan mind meld portrayed in Star Trek (" The Girl in the Fireplace"). He can apparently reverse this process, sharing his memory with another, as seen most recently in The Big Bang. Some humans can also enter the Doctor's memories after he enters theirs, as demonstrated by Madame de Pompadour (much to the Doctor's surprise) in "The Girl in the Fireplace", when she explains, "A door, once opened, may be stepped through in either direction." In " The Fires of Pompeii" the Doctor reveals that he is able to perceive the fabric of time, discerning "fixed points" and "points in flux"- moments when history must remain as it was originally versus moments when he can change or influence the original course of events, as well as all past, present and possible future events. It is revealed in the episode " The Unicorn and the Wasp" that if he has the right vitamins and minerals in the right order he can stop himself dying from a dose of cyanide.

The Doctor also exhibits some weaknesses uncommon to humans. For example, according to The Mind of Evil (1971), a tablet of aspirin could kill him. In Cold Blood, a process meant to decontaminate him of bacteria from the surface of Earth causes him intense pain, and he says it could have killed him if allowed to proceed to completion. In the Eighth Doctor Adventures novel The Adventuress of Henrietta Street the Doctor lost some of his biological advantages over humans when his second heart was surgically removed when it appeared to be poisoning him, resulting in him losing the ability to metabolise drugs in his system and his respiratory bypass system, but these are restored to him when he begins to grow a new heart after his old one 'dies' ( Camera Obscura). Events from the novels may or may not be canonical.

In his final serial, the Second Doctor states that Time Lords can live forever, "barring accidents." When "accidents" do occur, Time Lords can usually regenerate into a new body. However, it is stated in The Deadly Assassin that Time Lords can only regenerate a total of twelve times, giving a theoretical final total of thirteen incarnations. It may be possible to exceed this: in The Five Doctors the Time Lords offer the Master, who is inhabiting a Trakenite body, a regeneration cycle as reward for his help and cooperation, and at some point during the Time War they resurrected him, with his new body having at least one regeneration of its own. Regeneration is apparently optional, as in " Last of the Time Lords" the Master refuses to regenerate despite the Tenth Doctor's pleading. In addition, there are ways of killing a Time Lord that do not permit regeneration; for example, more than once it has been implied that stopping both the Doctor's hearts simultaneously would accomplish this. In the events of " The Impossible Astronaut", it appeared that shooting the Doctor during his regeneration into a Twelfth Doctor killed him permanently. However, " The Wedding of River Song" revealed that this was not actually the Doctor, but the Tesselecta robot pretending to be him, so the efficacy of a mid-regeneration killing has not been confirmed. The Chancellery Guard (Gallifrey's equivalent of a police force) are armed with stasers, weapons capable of suppressing regeneration.

In an October 2010 episode of the spin-off series, The Sarah Jane Adventures, when asked by Clyde how many times he can regenerate, the Doctor (Matt Smith) flippantly replies "507". Whether this is true or just a joke is unclear, but the writer of that episode, Russell T. Davies, said it was "...too good an opportunity to miss."

Other skills include his mental communication with other Time Lords, in some cases over a galaxy's distance. His skill with hypnosis is such that he requires only a second's glance into a subject's eyes to put him/her under his spell. The Doctor can read an entire book cover to cover in a second by thumb-flipping the pages before his eyes ( City of Death, " Rose", " The Time of Angels"). Though any medical skills he shows early in the series are rudimentary, by Remembrance of the Daleks he can perform sophisticated medical diagnoses merely by touching someone's ear. He is an excellent cricket player ( Black Orchid) and in " The Lodger" he proves to be a prodigiously talented footballer despite unfamiliarity with some of the game's basic rules. Though reluctant to engage in combat against living opponents, this is not for any lack of skill in doing so; the Doctor is conversant with both real and fictitious styles of unarmed combat (most obviously the "Venusian Aki-Do" practised by the Third Doctor), has won several swordfights against skilled opponents, and is able to make extremely difficult shots with firearms and, in one instance (in The Face of Evil), with a crossbow. Thanks to exposure to many of history's greatest experts, including those from the future, the Doctor is a talented boxer, musician, organist, scientist, singer (able to shatter windows with his voice), and has a PhD in cheesemaking ( The God Complex).

"Doctor who?"

In the first episode, Barbara addresses the Doctor as "Doctor Foreman", as this is the surname the Doctor's granddaughter Susan goes by, and the junkyard in which they find him bears the sign "I.M. Foreman". When addressed by Ian with this name in the next episode, the Doctor responds, "Eh? Doctor who? What's he talking about?" Later, when he realises that "Foreman" is not the Doctor's name, Ian asks Barbara, "Who is he? Doctor who?" (In an ultimately unused idea from documents written at the series' inception, Barbara and Ian would have subsequently referred to the Doctor as "Doctor Who", given their not knowing his name.)

Similarly, in the 2005 series premiere "Rose", when asked his name, the Doctor replies, "Just 'The Doctor'." New companion Rose Tyler later finds a website devoted to the Doctor on the Internet, run by a conspiracy theorist who has been tracking the Ninth Doctor's appearances throughout history, carrying the title "Doctor Who?" (see Doctor Who tie-in websites). The BBC launched a "real" version of this website with the idea that it is run by Mickey Smith, Rose's boyfriend (who has taken over the site following the death of its originator). Also, in the 2011 episode The Impossible Astronaut, Matilda, a nobleman's daughter, paints a semi-nude portrait of the Doctor. When her father comes charging in demanding to see him, she replies simply: "Doctor who?"

Although listed in the on-screen credits for nearly twenty years as "Doctor Who" or "Dr Who", the Doctor is never really called by that name in the series, except in a tongue-in-cheek manner. For example, in The Gunfighters the Doctor assumes the name of Doctor Caligari and subsequently responds to the question "Doctor Who?" with "yes, quite right". Also, question marks adorning his costuming in the 1980s seem to imply the "Who" moniker. The only real exceptions are the computer WOTAN in the serial The War Machines, which commands that "Doctor Who is required" and, towards the end of the Second Doctor serial Fury from the Deep, the Doctor is addressed as "Doctor Who" by Mr Harris during the dinner party. The Third Doctor's car, dubbed "Bessie", carried the plate WHO 1, the only ongoing reference to the "Doctor Who" enigma in the original series. The Third Doctor also later drove an outlandish vehicle called the " Whomobile" in publicity materials, but it is never referred to as such in the series, being simply known as "the Doctor's car" or "my car", as the Doctor puts it. The name "Doctor Who" is also used in the title of the serial Doctor Who and the Silurians, but this was a captioning error rather than an in-story mention. The only other time this occurs is in the title of Episode 5 of The Chase: "The Death of Doctor Who".

In the Fourth Doctor serial " The Armageddon Factor", the Doctor runs into a former class mate of his named Drax. Drax calls the Doctor Theta Sigma or "Thete" for short, an alias which is clarified as the Doctor's nickname at the Prydon Academy on Gallifrey in The Happiness Patrol.

In " The Christmas Invasion", the newly regenerated Doctor stumbles out of the TARDIS in a confused state in front of Jackie Tyler and Mickey. When Rose emerges from the TARDIS, she tells them that he is the Doctor, to which a confused Jackie replies "What do you mean that's the Doctor? Doctor Who?". The joke is used twice in " The Impossible Astronaut" by Matilda and, later, Canton Delaware. A similar version of this in-joke is told in the serials The Curse of Peladon, The Five Doctors and the audio commentary for Revelation of the Daleks reveals that Colin Baker tried to slip it into that serial when the Daleks fail to recognise him. In " The Girl in the Fireplace" (2006), Madame de Pompadour reads the Doctor's mind and remarks about his name, "Doctor who? It's more than just a secret, isn't it?"

In Series 7, " Asylum of the Daleks" the Doctor acknowledges the moniker with delight, after an episode in which a prisoner on the Dalek Asylum Planet wipes all Daleks' hive memory banks of any record of the Doctor. On entering the Dalek parliament, when asked to identify himself he says, "it's me, the Doctor, you know me, the oncoming storm, the Predator". The assembly of Daleks' response is: "Doctor who?". The Doctor returns to the TARDIS, dancing and revelling in the name Doctor Who.

In " The Snowmen", set in 1892, Clara chases after the Doctor (who's in a cab) and when she gets to him, she says "Doctor? Doctor who?".

In the podcast commentary on the BBC website, writer Steven Moffat suggests that, as the Doctor does not tell even his closest companions his name, there must be a "dreadful secret" about it. Within the same commentary, Moffat and actor Noel Clarke jokingly suggest his name to be "Curtis". Ironically, according to the in-vision commentary on the DVD release, David Tennant had to inform actress Sophia Myles (who played Madame de Pompadour) that she was not, in fact, revealing the Doctor's surname as she believed was the intent of the dialogue. In the 1996 telemovie, the recently regenerated and amnesiatic Eighth Doctor repeatedly screams to his reflection "Who am I?!" In " The Shakespeare Code", the Carrionite Lilith, unable to discover his true name, remarks, "Why would a man hide his title in such despair?" A psychically inspired human in " The Fires of Pompeii" remarks that his name "Doctor" is false and that his true name is in fact hidden. In Moffat's " Forest of the Dead", the character River Song reveals she knows the Doctor in his future, and it is implied that they shared a very intimate relationship. To gain his trust, she whispers something—inaudible to the audience—into his ear, which he later reveals was his real name. The Doctor states that there is "only one reason" he would reveal his name and that there is "only one time [he] could".

The dialogue joke was also used in 1981's unsuccessful pilot for K-9 and Company, wherein the Fourth Doctor's robotic dog, K-9, is discovered by his former companion, Sarah Jane Smith, and describes itself as being a gift to her from "The Doctor". Supporting character Brendan Richards asks, "Who's the doctor?" to which K-9 replies with its catch-phrase, "Affirmative." The show's events were subsequently referred to in The Five Doctors and the 2006 Doctor Who episode, " School Reunion".

Doctor Who spin-off media, which are of uncertain canonicity, have suggested that the character uses the name "the Doctor" because his actual name is impossible for humans to pronounce. For instance in the novel Vanderdeken's Children, it's told that the Doctor already told Sam his real name which is entirely alien and virtually unpronounceable. This is also repeated by companion Peri Brown in the radio serial Slipback. The Faction Paradox encyclopaedia The Book of the War states that all renegades from the Homeworld/Gallifrey abandon their names to symbolise how they leave their culture. Similarly, the novel Lungbarrow reveals that the Doctor's name has been struck from the records of his family and therefore cannot be spoken.

The character played by Peter Cushing in the films Dr. Who and the Daleks and Daleks – Invasion Earth: 2150 A.D. referred to himself as "Dr. Who". However, these films are not considered part of the same narrative continuity as the television series, as they were based upon two television serials featuring William Hartnell and made considerable alterations to the characters of the Doctor and his companions.

At the end of " Journey's End", Davros states "Never forget, Doctor, you did this. I name you forever, you are 'The Destroyer of Worlds".

" The Wedding of River Song" reveals that the Silence have been seeking to prevent the oldest question from being answered. The question is known as "The first question, the question that must never be answered, hidden in plain sight, the question that [The Doctor has] been running from all [his] life. Doctor who?"

Alias "The Doctor"

Quite apart from his name, why the Doctor uses the title of "The Doctor" has never been fully explained on screen. The Doctor, at first, said that he was not a physician, often referring to himself as a scientist or an engineer. However he does occasionally show medical knowledge and has stated on separate occasions that he studied under Joseph Lister and Joseph Bell. In The Moonbase, the Second Doctor mentions that he studied for a medical degree in Glasgow during the 19th Century. The Fourth Doctor was awarded an honorary degree from St. Cedd's College, Cambridge in 1960. He has also been mocked by his fellow Time Lords for adhering to such a "lowly" title as "Doctor", although in The Armageddon Factor he tells Drax that he achieved his doctorate, indicating it was at least a somewhat respectable title. In " The Girl in the Fireplace", he draws an analogy between the title and Madame de Pompadour's. In " The Sound of Drums", The Doctor remarks to the Master that they both chose their names and The Master, in response, remarks that it was sanctimonious of the Doctor to identify himself as "the man who makes people better;" one of the Master's assistants calls him a "doctor of everything". In The Mutants an official asks the Third Doctor if he is, in fact, a doctor, to which the Doctor replies "I am, yes"; when asked what he is qualified in, the Doctor replies, "Practically everything." The Fourth Doctor states that his companion, Harry Sullivan, is a Doctor of medicine, while he is "a doctor of many things" ( Revenge of the Cybermen). The Fifth Doctor claims to be a doctor "of everything" in Four to Doomsday, and a message is related from the Tenth Doctor in " Utopia" that he claims to be a doctor "of everything". In talking with Harry in Robot, the Doctor states "You may be a doctor, but I'm the Doctor. The definite article, you might say." In The Ark in Space The Fourth Doctor states that his doctorate is only honorary; the Tenth Doctor, however, considers the name to be his legitimate academic rank in " The Waters of Mars": in response to an order to give his name, rank and the nature of his business on the planet, he responds, "The Doctor; doctor; fun."

In an interview with The Age in 2003, Tom Baker mentioned that the Doctor is called so because he is "a doctor of time and relative dimension in space". Apart from being called a doctor of the TARDIS, the Doctor has also been referred to as just a "doctor of time travel."

The Telos novella Frayed by Tara Samms (which takes place prior to "An Unearthly Child") has the First Doctor being given that title by the staff of a besieged human medical facility on the planet Iwa, suggesting at the end that the Doctor liked the official title so much that he adopted it. However, this does not quite explain why the Time Lords use the same title in addressing him. The same story also has Jill, a young girl living in the facility, naming the Doctor's granddaughter "Susan" after Jill's mother. The canonicity of all non-television sources is uncertain.

In " A Good Man Goes to War", Dr River Song explains that, as the Doctor has travelled throughout space and time, cultures have adopted his name as a word for "healer and wise man". (Episode writer Moffat publicly suggested this as a fan in 1995, nine years before he began writing for the show.) In some worlds, however, "Doctor" has an entirely different definition. To the people of the Gamma Forests, his name came to mean "mighty warrior". Also in " A Good Man Goes to War", it is implied that River knows the baby cot was the Doctor's because she can read Gallifreyan and thus, read his actual name.

To make up for his lack of a practical name, the Doctor often relies upon convenient pseudonyms. In The Gunfighters, the First Doctor uses the alias Dr. Caligari. In The Highlanders, the Second Doctor assumes the name of "Doctor von Wer" (a German approximation of "Doctor Who"), and signs himself as "Dr. W" in The Underwater Menace. He similarly poses as "the Great Wizard Quiquaequod" in The Dæmons; 'Qui', 'quae', and 'quod' being, respectively, the masculine, feminine and neuter Latin translation of 'who' -- the Master was utilising Latin translation in the same serial, posing as "Mr Magister". The Eighth Doctor's companion Grace briefly refers to him by the alias "Dr. Bowman" in the 1996 Doctor Who television movie.

In The Wheel in Space, his companion Jamie McCrimmon, reading the name off of some medical equipment, tells the crew of the Wheel that the Doctor's name is "John Smith." The Doctor subsequently adopts this alias several times over the course of the series, often prefixing the title "Doctor" to it. This name is particularly prominent during his third incarnation when, as scientific advisor to UNIT, he gives it to Brigadier Lethbridge-Stewart to be put on his official credentials; the Seventh Doctor briefly used these old Dr John Smith credentials in Battlefield. In the 1996 telemovie, Chang Lee (who had only met the semi-conscious Seventh Doctor minutes earlier and did not know his identity) gives him the name John Smith on the emergency medical treatment form; the Tenth Doctor is admitted to hospital under that name again when he meets Martha Jones in " Smith and Jones". The Tenth Doctor is also using the name when he unsuspectingly meets Sarah Jane Smith whom he had not seen for several incarnations. Suspicious but in public, Sarah Jane mentions that she used to know a man who sometimes used that name. He explains, "It's a very common name." In response, she remarks, "He's a very un-common man." When posing as his own 'Living Flesh' doppelgänger in " The Rebel Flesh", the Eleventh Doctor suggests the others call him John Smith for convenience. Nevertheless, in " Closing Time", he takes the job as a sales clerk and wears a store name badge reading "The Doctor" rather than "John Smith" or a similar alias.

In the audio adventure, The Sirens of Time, when the Fifth Doctor is asked his name, this conversation ensues:

"I'm the Doctor."
"Doctor? That's a profession, not a name."
"It's all I have."

In " New Earth", it is implied that the Doctor is part of the prophecy of the Face of Boe and is referred to as "The Lonely God." In "Tooth and Claw", having landed in Scotland, the Tenth Doctor introduces himself as "Dr. James McCrimmon", from the township of Balamory, in reference to the Second Doctor's companion Jamie McCrimmon who had first given him the John Smith alias. Later in that episode, the Doctor is knighted by Queen Victoria as "Sir Doctor of TARDIS"; she then declared him an enemy of the crown and banished him for all time, with Torchwood in part created to enforce this exile.

To his greatest enemies, the Daleks, the Doctor is known as the Ka Faraq Gatri, the "Bringer of Darkness", or "Destroyer of Worlds". This is first mentioned in the novelisation of Remembrance of the Daleks by Ben Aaronovitch and subsequently taken up in the spin-off media, particularly the Virgin New Adventures books and the Doctor Who Magazine comic strip. Davros uses the title "Destroyer of Worlds" to describe the Doctor in " Journey's End." In the Virgin New Adventures novel Love and War, the Doctor is referred to as "The Oncoming Storm" by the Draconians (whose word for it is "Karshtakavaar"); according to the episode " The Parting of the Ways", the same title is used by the Daleks. The Doctor refers to himself as "The Oncoming Storm" in " The Lodger." In " Asylum of the Daleks", it is stated that Daleks refer to the Doctor as "The Predator". The Virgin New Adventure Zamper establishes that the Chelonians refer to him as "Interfering Idiot".

In The End of Time, it is mentioned that after he smote a demon in the 13th century, the residents of a convent called the Doctor the "sainted physician."

The series has also occasionally toyed with the Doctor's identity (or lack thereof). In the first part of The Mysterious Planet, the Doctor suggests writing a thesis on "Ancient Life on Ravolox, by Doctor...", but is interrupted by Perpugilliam "Peri" Brown. In The Armageddon Factor, the Time Lord Drax addresses the Fourth Doctor as "Thete", short for "Theta Sigma". Later, in The Happiness Patrol, this was clarified as a nickname from the Doctor's University days; he is called by this name again in the Paul Cornell novel Goth Opera. In Remembrance of the Daleks, the Seventh Doctor produces a calling card with a series of pseudo-Greek letters inscribed on it (as well as a stylised question mark). This may be a reference to Terrance Dicks's and Malcolm Hulke's book The Making of Doctor Who (1972), which claims that the Doctor's true name is a string of Greek letters and mathematical symbols.

The question mark motif was common throughout the eighties, in part as a branding attempt. Beginning with season eighteen, the Fourth through Seventh Doctors all sported costumes with a red question mark motif (usually on the shirt collars, except for the Seventh Doctor—it appeared on his pullover and in the shape of his umbrella handle). In the 1978 serial The Invasion of Time, the Fourth Doctor is asked to sign a document; although the signature itself is not directly seen on screen, his hand movements clearly indicate that he signs it with a question mark. A similar scene occurs with the Seventh Doctor in Remembrance of the Daleks.

In " The Lodger", the Eleventh Doctor states, "I'm the Doctor. Well, they call me 'the Doctor', I don't know why; I call me 'the Doctor' too, still don't know why." By the Eleventh Doctor, already well known and recognised wherever or whenever he went due to the near thousand years of his journeys and after learning the time and place of his death he rebelled against his destiny by spending a couple of hundred years purposely trying to be seen and remembered, the Doctor recognises the error of his ways when in A Good Man Goes to War he is told that 'Doctor' is "The word for “healer” and “wise man,” thoughout the universe. We get that word from you, you know. But if you carry on the way you are, what might that word come to mean? To the people of the Gamma Forests, the word doctor means “mighty warrior.” The Doctor then tries to adopt a more covert approach to his adventures helped enormously when in Asylum of The Daleks the Dalek hive memory of him is wiped and the entire race of his most fearsome enemy no longer remembers him.

On-screen credits

In the early years of the spin-off comic strips, books, films and other media, the character was initially called "Doctor Who" (or just "Dr Who") in the stories as a matter of course. This usage declined as the years went by.

From the first television serial through to Logopolis (the last story of Season 18 and also of the Tom Baker era), the lead character was credited as "Doctor Who" (or sometimes "Dr Who"). Starting from Peter Davison's first story, Castrovalva (the first story of the series' Season 19) to the end of Season 26, he is credited simply as "The Doctor".

This format is continued in the 1996 television movie for Paul McGann's credit, while Sylvester McCoy's incarnation is credited as "The Old Doctor". For the 2005 revival starring Christopher Eccleston, the credit reverted to "Doctor Who". However, in " The Christmas Invasion", and subsequent stories featuring David Tennant, the character is once again identified in the closing credits as "The Doctor", with " The Parting of the Ways" being the only episode to feature David Tennant in which he is credited as playing "Doctor Who". According to Doctor Who Magazine No. 367 this reversion was specifically requested by Tennant. The lead character credit has remained "The Doctor" for Matt Smith's tenure as the eleventh incarnation.

In the 2007 finale episode " The Sound of Drums", the Doctor tells the Master, "You chose it [his name]. Psychiatrist's field day." In response, the Master states, "As you chose yours. The man who makes people better. How sanctimonious is that?"

Changing faces

The changing of actors playing the part of the Doctor is explained within the series by the Time Lords' ability to regenerate after suffering illness, mortal injury or old age. The process repairs all damage and rejuvenates his body, but as a side effect it changes his physical appearance and personality. This ability was not introduced until producers had to find a way to replace the ailing William Hartnell with Patrick Troughton and was not explicitly called "regeneration" until Jon Pertwee's transformation to Tom Baker at the climax of Planet of the Spiders (1974). On screen, the transformation from Hartnell to Troughton was called a "renewal" and from Troughton to Pertwee a "change of appearance".

The original concept of regeneration or renewal was that the Doctor's body would rebuild itself in a younger, healthier form. The Second Doctor was intended to be a literally younger version of the First; biological time would turn back, and several hundred years would get taken off the Doctor's age, rejuvenating him. In practice, however, after the Doctor stated his age in the Second Doctor serial The Tomb of the Cybermen (1967), the Doctor's age has been recorded progressively, however many regenerations the Doctor goes through (but see below). In six out of ten transitions, the new actor was younger than his predecessor had been when he began the role. In the revived series the pattern is resumed with the transition of the Ninth to the Tenth and the Tenth to the Eleventh Doctor, although current showrunner Steven Moffat is on record stating the intention was to cast an actor in his mid 30s to 40s for the role of the Eleventh Doctor, despite casting Matt Smith who is the youngest actor to ever have played the role.

The actors who have played the Doctor in the series, and the dates of their first and last regular television appearances in the role, are:

Order	Actor	Start		End
		Date	Age	Date	Age
First Doctor	William Hartnell	23 November 1963	55	29 October 1966	58
Second Doctor	Patrick Troughton	29 October 1966	46	21 June 1969	49
Third Doctor	Jon Pertwee	3 January 1970	50	8 June 1974	54
Fourth Doctor	Tom Baker	8 June 1974	40	21 March 1981	47
Fifth Doctor	Peter Davison	21 March 1981	29	16 March 1984	32
Sixth Doctor	Colin Baker	16 March 1984	40	6 December 1986	43
Seventh Doctor	Sylvester McCoy	7 September 1987	44	27 May 1996	53
Eighth Doctor	Paul McGann	27 May 1996	36	27 May 1996	36
Ninth Doctor	Christopher Eccleston	26 March 2005	41	18 June 2005	41
Tenth Doctor	David Tennant	18 June 2005	34	1 January 2010	38
Eleventh Doctor	Matt Smith	1 January 2010	27	current

Personality

Throughout his regenerations, the Doctor's personality has retained a number of consistent traits. Its most notable aspect is an unpredictable, affable, clownish exterior concealing a well of great age, wisdom, seriousness and even darkness. While the Doctor can appear childlike and jocular, when the stakes rise, as, for example, in Pyramids of Mars, he will often become cold, driven and callous. Another aspect of the Doctor's persona, which, though always present, has been emphasised or downplayed from incarnation to incarnation, is compassion. The Doctor is a fervent pacifist and is dedicated to the preservation of sentient life, human or otherwise, over violence and war, even going so far as to doubt the morality of destroying his worst enemies, the Daleks, when he has the chance to do so in Genesis of the Daleks, and again in Evolution of the Daleks. He also, in The Time Monster, begs Kronos to spare the Master torment or death, unintentionally winning the evil Time Lord's freedom, which he tells Jo Grant was preferable anyway, and forgives the Master for his actions in The Sound of Drums and Last of the Time Lords, vowing to take responsibility for his former friend.

Nonetheless, the Doctor will kill when given no other option and occasionally in self-defence; examples of this can be seen in The Tomb of the Cybermen, The Dominators, The Invasion, The Krotons, Spearhead from Space, The Sea Devils, The Three Doctors, The Brain of Morbius, The Talons of Weng-Chiang, The Invasion of Time, Earthshock, Arc of Infinity, Vengeance on Varos, The Two Doctors, Silver Nemesis, " World War Three", " The Christmas Invasion", " Tooth and Claw", " The Age of Steel", " The Runaway Bride", " Smith and Jones" and most notably in Remembrance of the Daleks when he arranges for the planet Skaro to be destroyed; it has also been stated numerous times in the series, beginning in 2005, that he was responsible for destroying both the Dalek and Time Lord races in order to end the Time War. Another example of the Doctor purposely taking a life is The Sontaran Experiment, where he tells his companion Harry Sullivan to remove a device from the Sontaran ship, which causes the death of the Sontaran, something the Doctor knew would happen but Harry did not. In the 2005 episode " The End of the World", the Doctor teleports Cassandra back onto the ship and does nothing to prevent her death, even ignoring her cries for help and pity. Similarly, in " Dinosaurs on a Spaceship", he strands Solomon on a spacecraft with a homing device to which several missiles have locked on, effectively consigning him to death. In situations where fixed points in history must be preserved, the Doctor is sometimes faced with hard choices resulting in the deaths of many; In The Visitation he started the Great Fire of London, and in The Fires of Pompeii he caused the volcano above Pompeii to erupt, which killed everyone in the city (but saved the rest of the world). On other occasions he is seen to be critical of others who use deadly force, such as his companions Leela in The Face of Evil and Talons of Weng-Chiang, or Jack Harkness in " Utopia".

The Doctor has an extreme dislike for weapons such as firearms or rayguns and will often decline to use them even when they are convenient. The Tenth Doctor was especially put off by guns, going out of his way to make his feelings known. In Doomsday the Daleks declare the Doctor is unarmed, to which he replies "That's me. Always." In The Doctor's Daughter he is enraged at the death of Jenny and points a gun at the head of the man who shot her before throwing it away and yelling "I never would!". He has proven capable of using weapons effectively when necessary, as seen in Resurrection of the Daleks and Revelation of the Daleks. In The End of Time he hit a small diamond with a single shot to destroy a machine and prevent the destruction of time itself. He will occasionally use a firearm as a convenient way to bluff his way through a situation, hoping that his foe will not suspect that he does not intend to shoot. He will also occasionally present non-threatening items as weapons so as to fool his enemies, and buy himself time (such as threatening to kill a tribesman with a "deadly jelly baby" in The Face of Evil, brandishing a water pistol in The Fires of Pompeii, or pretending a Jammie Dodger to be a Tardis self-destruct device in " Victory of the Daleks"). However, in " A Town Called Mercy", he throws Kahler-Jex out of the town, where he knows the Gunslinger will find and kill him, and aims a pistol at him to keep him out.

The Doctor has a deep sense of right and wrong, and a conviction that it is right to intervene when injustice occurs, which sets him apart from his own people, the Time Lords, and their strict ethic of non-intervention.

Although throughout his regenerations the Doctor remains essentially the same person, each actor has purposely imbued his incarnation of the role with distinct quirks and characteristics and the production teams purposefully dictate new personality traits for each actor to portray.

Accent

Different actors have used different regional accents in the role. The first six Doctors spoke in Received Pronunciation or "BBC English", as was standard on British television at the time. Sylvester McCoy used a very mild version of his own Scottish accent in the role, and Paul McGann spoke with a faint Liverpudlian lilt. Only rarely is this even addressed in the series. In the case of the Eighth Doctor, who is identified by American characters as "British," he seems only slightly conscious of the way he sounds, responding with "yes, I suppose I am." When the Ninth Doctor's accent is clearly described as " Northern," he responds with the line "lots of planets have a North."

Another example is in The Tomb of the Cybermen when the Doctor is identified as "English" and, dissembling, plays along. Though David Tennant speaks with a natural Scottish accent, he played the Tenth Doctor with an Estuary accent (apart from when, in the Highlands-set episode " Tooth and Claw" the character is pretending to be a local). According to producer Russell T Davies, this was intended as a consequence of spending so much time with Rose. "The Christmas Invasion" would have alluded to this, but the line was cut. Davies also said that after Eccleston's accent, he did not want Tennant "touring the regions" with a Scottish one, and so asked Tennant to affect the same accent he used for the earlier BBC period drama Casanova.

In the Big Finish audio adventure The Sirens of Time the captain aboard a German U-boat assumes he is English because of the way he pronounces his words: "So, you speak German, ... but you speak it like an English gentleman."

Changing fashions

The Doctor's clothing has been equally distinctive, from the distinguished Edwardian suits of the First Doctor to the Second Doctor's rumpled, clownlike Chaplinesque attire to the dandy-esque frills and velvet of the Third Doctor's era. The Fourth Doctor's long frock coat, loose fitting trousers, occasionally worn wide-brimmed hat and trailing, multistriped scarf added to his somewhat shambolic and bohemian image; the Fifth's Edwardian cricketeer's outfit suited his youthful, aristocratic air as well as his love of the sport (with a stick of celery on the lapel for an eccentric touch though in The Caves of Androzani it is revealed to turn purple when exposed to gases the Doctor is allergic to); and the Sixth's multicoloured jacket, with its cat-shaped lapel pins, reflected the excesses of 1980s fashion. The Seventh Doctor's outfit—a straw hat, a coat with two scarves, a tie, checked trousers and brogues/wingtips—was more subdued and suggestive of a showman, reflecting his whimsical approach to life. In later seasons, as his personality grew more mysterious, his jacket, tie, and hatband all grew darker.

Throughout the 1980s, question marks formed a constant motif, usually on the shirt collars or, in the case of the Seventh Doctor, on his sleeveless jumper and the handle to his umbrella. The idea was grounded in branding considerations, as was the movement starting in Tom Baker's final season toward an unchanging costume for each Doctor, rather than the variants on a theme employed over the first seventeen years of the programme. When the Eighth Doctor regenerated, he clad himself in a 19th century frock coat and shirt based around a Wild Bill Hickok costume, reminiscent of the out-of-time quality of earlier Doctors and emphasising the Eighth Doctor's more Romantic persona.

In contrast to the more flamboyant outfits of his predecessors, the Ninth Doctor wore a nondescript, worn black leather jacket, V-neck jumper and dark trousers. Eccleston stated that he felt that such definitive "costumes" were passé and that the character's trademark eccentricities should show through their actions and clever dialogue, not through gimmicky costumes. Despite this, there is a running joke about his character that the only piece of clothing he changes is his jumper, even when trying to "blend into" a historical era. The one exception, a photograph of him taken in 1912, wearing period gentleman's clothing, resembles the style of the Eighth Doctor.

The Tenth Doctor sports either a brown or a blue pinstripe suit – usually worn with ties – a tan ankle-length coat and Converse trainers, the latter recalling the plimsolls worn by his fifth incarnation. Also like that incarnation (and his first one), he occasionally wears spectacles: a pair with black, thick-rimmed frames. In the 2007 Children in Need special he states that he doesn't actually need glasses to see, but rather wears them to "look a bit clever." On some occasions he wears a black tuxedo with matching black trainers. In interviews, Tennant has referred to his Doctor's attire as geek chic. According to Tennant he had always wanted to wear the trainers. The overall costume, however, was influenced by an outfit worn by Jamie Oliver in a TV interview on the talk show Parkinson.

The Tenth Doctor says in " The Runaway Bride" that, like the TARDIS, his pockets are bigger on the inside. The Second, Fourth, Sixth, Seventh and Eleventh Doctors routinely carried numerous items in their coats without this being conspicuous.

The Eleventh Doctor's appearance has been described as appearing like "an Oxford professor", with a tweed jacket, red or blue striped shirt, red or blue bow tie, black or grey trousers with red or blue braces, and black boots. He maintains "Bow ties are cool" even when his companions do not agree, and is delighted to meet Dr Black, the first man who agrees with him, in the episode " Vincent and the Doctor". As a running gag, he exhibits attraction to unusual hats, like a fez, a pirate hat, and a stetson, often only to have them destroyed by River Song shortly afterwards.

Transitions

Save for the off-screen transition between the Eighth and Ninth Doctors, to date each regeneration has been worked into the continuing story. Also, most regenerations (save the Second-to-Third and Eighth-to-Ninth transitions) have been portrayed on-screen, in a handing over of the role. The following list details the manner of each regeneration:

1. First Doctor (William Hartnell): Frail and steadily growing weaker throughout The Tenth Planet, the doctor collapses at the serial's end.
2. Second Doctor (Patrick Troughton): a forced "change in appearance" and exile to Earth by the Time Lords in the closing moments of The War Games.
3. Third Doctor (Jon Pertwee): radiation poisoning from the Great One's cave of crystals on the planet Metabilis 3 at the end of Planet of the Spiders.
4. Fourth Doctor (Tom Baker): fell from the Pharos Project radio telescope in Logopolis and was assisted in the regeneration by a mysterious "in-between" incarnation identified as "The Watcher".
5. Fifth Doctor (Peter Davison): spectrox toxaemia poisoning, contracted near the start of The Caves of Androzani.
6. Sixth Doctor (Colin Baker): suffered great injuries when the Rani attacked the TARDIS and caused it to crash land at the start of Time and the Rani.
7. Seventh Doctor (Sylvester McCoy): died in San Francisco during exploratory heart surgery by a doctor unfamiliar with Time Lord physiology, after being hospitalised for non-life threatening gunshot wounds in the 1996 television movie.
8. Eighth Doctor (Paul McGann): unknown cause of death.
9. Ninth Doctor (Christopher Eccleston): cellular degeneration caused by absorbing the energies of the time vortex from Rose Tyler, which she in turn had absorbed through the heart of the TARDIS in " The Parting of the Ways".
10. Tenth Doctor (David Tennant): radiation poisoning incurred while saving the life of Wilfred Mott in The End of Time.

Only the Doctor's first regeneration (Hartnell to Troughton) occurs due to natural causes – the Doctor is showing increasing signs of age, and comments that his body is "wearing a bit thin," though this is apparently exacerbated by the energy drain from Mondas. All of the other regenerations have been caused by some external factor, such as radiation poisoning, infection or fatal injuries.

In the original series, with the exception of the change from Troughton to Pertwee, regeneration usually occurred when the previous Doctor was near "death". The changeover from McCoy to McGann was handled differently, with the Doctor actually dying and being dead for quite some time before regeneration occurred. The Eighth Doctor comments at one point in the television movie that the anaesthesia interfered with the regenerative process, and that he had been "dead too long", accounting for his initial amnesia. Kate Orman's novel The Room with No Doors, set just before the regeneration, also notes that this is one of the few regenerations in which the Doctor was not conscious and aware that he was dying.

The 2005 series began with the Ninth Doctor already regenerated and fully stabilised, with no explanation given. In his first appearance in "Rose", the Doctor looked in a mirror and commented on the size of his ears, suggesting to some viewers that the regeneration may have happened shortly prior to the episode, or that he has not examined himself in the mirror recently. Some draw the conclusion that the Ninth Doctor's appearances in old photographs, without being accompanied by Rose, may also suggest that he had been regenerated for some time, but these appearances could have also occurred afterwards. Russell T Davies, writer/producer of the new series, stated in Doctor Who Magazine that he has no intention of showing the regeneration in the series, and that he believed the story of how the Eighth Doctor became the Ninth is best told in other media. In Doctor Who Confidential Davies revealed his reasoning that, after such a long hiatus, a regeneration in the first episode would not just be confusing for new viewers but also lack dramatic impact, as there would be no emotional investment in the character before he was replaced.

Regenerations

It was established in The Deadly Assassin (1976) that a Time Lord can regenerate twelve times before permanently dying – a total of thirteen incarnations. In the 1996 television movie the Eighth Doctor explicitly said that a Time Lord has "thirteen lives". (The Doctor's enemy, The Master has, however, been shown circumventing this limit on several occasions.) In Death of the Doctor (a 2010 episode of The Sarah Jane Adventures), the Eleventh Doctor indicated to Clyde Langer that he could regenerate 507 times. Early news reports, before the episode was broadcast, suggested he would say there is no limit to the number of regenerations. However, writer Russell T. Davies has confirmed that the line was not intended to be taken seriously.

In " The Christmas Invasion" it was stated the regenerative cycle creates a large amount of energy that suffuses the Time Lord's body. As demonstrated by the Tenth Doctor for the first time in that story, in the first fifteen hours of regeneration this energy is enough to even rapidly regrow a severed hand. This is in keeping with earlier serials, such as Robot, where the newly -regenerated Fourth Doctor splits a brick with his bare hand, and also in the 1996 television movie, where the Doctor is depicted battering down a heavy steel door in a hospital morgue.

The Doctor's regenerations are usually a result of his previous incarnation sustaining mortal injury or (in one case) having a change forced on him by the Time Lords. Other Time Lord regenerations, like Romana's, have not been as dramatic or painful.

The Doctor frequently experiences a period of instability and partial amnesia following regeneration. Some post-regeneration experiences have been more difficult than others. In particular, the Fifth Doctor began reverting to his previous personalities and required the healing powers of the TARDIS's "Zero Room" to recuperate ( Castrovalva). The Sixth Doctor experienced extreme paranoia and flew into a murderous rage, nearly killing his companion ( The Twin Dilemma). The Eighth Doctor experienced amnesia (1996 Doctor Who television movie) however this particular episode of amnesia was brought on as an adverse reaction by his alien physiology to the anaesthetics used by the surgeons attempting to save his life.

The regeneration from Eighth to Ninth Doctors has never yet been revealed on film or television. The regeneration from the Ninth to the Tenth Doctor at first seemed smooth, with the Doctor regenerating standing up for the first time (" The Parting of the Ways"). However, shortly thereafter he began to experience spasms and became somewhat manic, frightening his companion as he pushed the TARDIS to dangerous extremes ( Children in Need mini-episode). After crash-landing the TARDIS, the Doctor collapsed and remained unconscious for most of the next fifteen hours (" The Christmas Invasion"). The experience was traumatic enough to cause one of his hearts to temporarily stop beating.

The newly regenerated Tenth Doctor, since it was within the first 15 hours of his regeneration and he had leftover regeneration energy, was able to regrow his hand when it was severed at the wrist during a swordfight with the Sycorax leader.

The TARDIS also appears to aid in the regenerative process. Of the four occasions the Doctor regenerates outside the TARDIS, three are initiated by Time Lords: one forced on him before banishment to Earth (The War Games), one requiring a Time Lord to give the Doctor's cells a "little push" to start the process (Planet of the Spiders), and one needing the Watcher, which the Doctor's travelling companions believed to be some version of the Doctor himself (Logopolis). The Eighth Doctor apparently occurred a few hours after he had actually "died", leaving him with temporary amnesia (the 1996 television movie) due to his body's adverse reaction to earth medicines.

In " Journey's End", the Tenth Doctor manages to avert his own regeneration, using some of the energy to heal himself then channelling the remaining energy into his severed hand, thus retaining his appearance and personality. The question of whether this partial regeneration process uses up one of this thirteen incarnations is left open. Later in the episode, the energy left over from the regeneration forms a "new" Doctor when Donna Noble inadvertently causes a "human-time lord biological metacrisis". This Doctor is part Time Lord and part human, possessing the Doctor's memories and physical appearance but also inheriting some of Donna Noble's personality traits. The part-human Doctor also has only one heart, ages like a human, and cannot regenerate. At the same time, the residual energy imbues Donna with the vast intellect of a Time Lord. However, the knowledge is too much for her human mind to handle and at the end of the episode the Doctor has to block all her memories of her time with him to save her life.

The End of Time finally shows the Tenth Doctor fully regenerating into the Eleventh Doctor, in a particularly violent fashion that causes severe damage to the TARDIS.

" The Impossible Astronaut" shows the Eleventh Doctor starting to regenerate after being attacked by the eponymous astronaut, but the regeneration is interrupted with a second attack and the Doctor is killed as a result. However, it was later revealed that it was actually the Teselecta ship impersonating the Doctor that was shot, not the Doctor himself.

" Let's Kill Hitler" featured River Song using her remaining regenerations to save the Doctor.

In " The Angels Take Manhattan", the Eleventh Doctor uses some of his regeneration energy to heal River Song's wrist, which she had broken in order to escape the grip of a Weeping Angel. River becomes upset and scolds the Doctor for wasting his energy on her.

Continuity curiosities

Over the years, different writers and production teams have introduced their own twists to the Doctor's character, sometimes as part of a grand creative reinvention; others, out of narrative convenience or outside pressures. Without one driving vision to maintain continuity, newer details may occasionally seem to contradict earlier ones. Other details—sometimes significant ones—are later ignored, sometimes leading to argument amongst series fans as to how, or whether, these details apply in a broader context.

In the early serials The Edge of Destruction and The Sensorites, it appeared that the First Doctor had only a single heart. The novel The Man in the Velvet Mask by Daniel O'Mahony suggests that Time Lords only grow their second heart during their first regeneration (speculated earlier by John Peel in The Gallifrey Chronicles). In The Mind of Evil, " The Christmas Invasion", " The Shakespeare Code", and " The Power of Three", one of the Doctor's hearts temporarily stops beating due to intense trauma.

During his first regeneration the Doctor's clothes (save for his cloak and ring, both of which quickly thereafter fall off) changed along with his body ( The Power of the Daleks); on all subsequent regenerations the new Doctor generally continues to wear the clothing he regenerated in until he selects a new outfit (though the regeneration from the Fourth to the Fifth Doctor included a change of footwear).

In The Brain of Morbius (produced shortly before The Deadly Assassin), visual images displayed during a mental battle between the Fourth Doctor and Morbius can be taken as implying that the Doctor had at least eight incarnations prior to the First Doctor. However, multiple dialogue references throughout the series (particularly in The Three Doctors, Mawdryn Undead and The Five Doctors) contradict this, as well as the fact that the Doctor has regenerated six times since then (as stated in "School Reunion"). Explanations have included theories that the images were of Morbius's previous incarnations (two images that are certainly Morbius also appear, and the game seems to have a symmetrical arrangement), or false images induced by the Doctor. The Doctor Who novels have suggested that these may have been faces of the Other, a figure from Gallifrey's ancient past and the genetic predecessor of the Doctor. The producers, however, intended that these were figures from the Doctor's past. Producer Philip Hinchcliffe has said, "We tried to get famous actors for the faces of the Doctor. But because no one would volunteer, we had to use backroom boys. And it is true to say that I attempted to imply that William Hartnell was not the first Doctor."

In the Sixth Doctor story arc The Trial of a Time Lord, a Time Lord with the title of the Valeyard (played by Michael Jayston) was revealed to be a potential future Doctor, a "distillation" created somewhere between his twelfth and final incarnations and embodying all the evil and malevolence of the Doctor's dark side. The Valeyard was defeated in his attempt to actualise himself by stealing the Sixth Doctor's remaining regenerations, however, and so may never actually come to exist.

The idea of an "in-between" version of the Doctor has its precedents. In Planet of the Spiders, a Time Lord's future self (described as a "distillation" of the future incarnation) was shown to exist as a corporeal projection that assisted his then-current incarnation. In Logopolis, an eerie and mysterious white-clad figure known as the Watcher assisted in the transition between the Fourth and Fifth Doctors. Nyssa commented that the Watcher "was the Doctor all the time" as he merged with the supine form of the fourth Doctor, regeneration beginning just before the merging is complete.

Perhaps the most controversial element from the 1996 television movie was the revelation that the Doctor is half-human ("on [his] mother's side"). The spin-off novels and audios have tried various methods to explain this revelation, suggesting that the Doctor retained some human DNA from his time as Dr John Smith (in which the Doctor, using bought technology, became biologically human with a different persona unaware of his Time Lord self) in the Virgin New Adventures novel Human Nature, or that his origins have become muddied by agents manipulating his personal timestream (the Eighth Doctor Adventures novel Unnatural History), hinting that it is only the Eighth Doctor who is half human, or that only his mother's incarnation at the time of his birth was Human. Kate Orman's novel The Room with No Doors features a time-travelling Victorian lady, Penelope Gate, who later books, such as Unnatural History and The Gallifrey Chronicles, hint may be the Doctor's mother, but do not elaborate on how this came to pass. In the New Series Adventures novel The Deviant Strain by Justin Richards, the Doctor comments that his DNA is "close" to that of humans. In the IDW Comics story "The Forgotten", the Eighth Doctor remarks that he simply convinced the Master he was half-human, "with nothing more than a wide-eyed expression, a couple of words, and a half-broken Chameleon Arch." However, as noted above, the canonical nature of the novels and comics is uncertain. The idea of a "half-human" Doctor is further discredited by the 2008 series finale " Journey's End", wherein the Doctor expresses dismay at his "half-human" double, and explicitly states that a human/Time Lord cross such as Donna becomes in that story has never existed before; events later in the episode show the latter combination to be inherently unstable. Furthermore, it was heavily implied by Russell T. Davies that "The Woman" in The End of Time is the Doctor's mother, and she is clearly one of the Time Lords with a vote on the Council. Despite all this, the notion that the Doctor is part human could certainly explain why he has always held such a strong affinity and protective nature towards the human race.

The Time Lord ability to change species during regeneration is referenced by the Eighth Doctor in relation to the Master in the television movie, being supported by Romana's regeneration scene in the 1979 serial Destiny of the Daleks. The Daleks also implied during the events of The Daleks' Master Plan (1965–66) that the First Doctor's humanoid form is not his actual appearance. The new series has not made any allusions to mixed parentage, simply referring to the Doctor as "alien" or "Time Lord". However, the trade paperback Doctor Who: The Legend Continues by Justin Richards, published to coincide with the new series, refers to the Doctor as half-human. The 2007 Tenth Doctor episodes " Human Nature" and " The Family of Blood", adapted from the above-mentioned Seventh Doctor novel, Human Nature, also show the Doctor using technology to become biologically human, although he does so through Time Lord science. Later, in " Utopia", the Master is revealed to have undergone the same process.

When incarnations meet

Due to time travel, it is possible for the Doctor's various incarnations to encounter and interact with each other, although this is supposed to be prohibited by the First Law of Time (as stated in The Three Doctors) or permitted only in the "gravest of emergencies" ( The Five Doctors). In the 1963–1989 television series, such encounters were seen on three occasions, in The Three Doctors (1972), The Five Doctors (1983) and The Two Doctors (1985). In Day of the Daleks (1972), the Third Doctor and Jo Grant very briefly met their future selves due to a glitch during a temporal experiment (the serial was supposed to end with the same scene depicted from the perspective of the "other" Doctor and Jo, but was excised because it was anticlimactic). In " Father's Day" (2005), the Ninth Doctor and Rose observed but did not interact with past versions of themselves; when Rose changed history, the earlier selves – after momentarily noticing Rose running past – vanished and a temporal paradox was created that attracted the extradimensional Reapers. The Tenth and Fifth Doctors met in the TARDIS in the mini-episode " Time Crash", which aired on 16 November 2007 as part of the BBC's annual Children in Need appeal. This marks the only time the Doctor has met a previous incarnation since the show's revival. Although the scene aired outside the series itself, it was established as taking place between the events of " Last of the Time Lords" and " Voyage of the Damned."

The BBC novel The Eight Doctors was written by respected Doctor Who writer Terrance Dicks, the same author who wrote The Five Doctors. In it, he tries to reconcile the continuity errors of the 1996 movie, while having the Eighth Doctor meet and interact with each of his previous selves.

Physical contact between two versions of the same person can lead to an energy discharge that shorts out the "time differential". This is apparently due to a principle known as the Blinovitch Limitation Effect, and was seen when the past and future versions of Brigadier Lethbridge-Stewart touched hands in Mawdryn Undead. Oddly, the Doctor's incarnations do not appear to suffer this effect when encountering each other and shaking hands. This has never been explained. An essay in the About Time series by Lawrence Miles and Tat Wood suggests that Time Lords are somehow exempt from the effect by their very nature. Rose Tyler is seen holding an infant version of herself in "Father's Day", with no visible energy discharge, but the contact does allow the Reapers to enter the church in which the Doctor and several others are taking refuge. While doing a live commentary on the episode at the 2006 Bristol Comic Expo, episode author Paul Cornell said that this is supposed to be due to the Blinovitch Limitation Effect, even though it is not mentioned by name. He also suggested that the lack of a spark may be down to the fact that the Time Lords were no longer around to manage anomalies.

The interaction of the Doctor's various incarnations produces a continuity anomaly that requires suspension of disbelief on the part of viewers, as one may assume that his past selves would forget that he would later regenerate. In Castrovalva, the newly regenerated Fifth Doctor clearly indicates that the outcome of his regeneration cannot be predicted; however, the Fifth Doctor should have had memories from his earlier incarnations of having met himself per the events of The Two Doctors and The Five Doctors. Also, the Second, Third and Fifth Doctors should be already familiar with the events of The Five Doctors, having already lived through them multiple times. It has been suggested in fandom that the Time Lords erase the Doctor's memory after such encounters (and in The Two Doctors there is mention of Dastari administering to the Second Doctor a drug that he bemoans "affects the memory"); the novel The Empire of Glass features the First Doctor directly after his return from the events of The Three Doctors, his memory of the adventure having been totally erased barring a vague recollection of meeting "a dandy and a clown". The Virgin Missing Adventures novel Cold Fusion by Lance Parkin suggests that memory-erasure is sometimes, but not always, due to something called "Blinovitch Conservation".

In the 2006 episode " School Reunion", the Tenth Doctor and Sarah Jane Smith both seem to indicate in dialogue that they haven't seen each other since her departure from the TARDIS in The Hand of Fear, although this contradicts their having met later during The Five Doctors. She, in that story, does not realise that the Fifth Doctor is a later incarnation of the third and fourth Doctors with whom she had previously travelled. In "Time Crash", the Tenth Doctor remembers and reproduces what he saw himself do when he was the Fifth Doctor, a fact that seems to surprise the Fifth Doctor himself.

Russell T Davies has expressed a dislike for stories in which multiple incarnations of the Doctor meet, stating that he believes they focus more on the actors than on the story itself. David Tennant had shown enthusiasm for the idea of a multi-Doctor story, but has expressed doubts about the practicality of shows involving multiple previous Doctors, given that three of the actors who played the character are now deceased.

Since the series revival, there has been one multi-Doctor story, the Children in Need special Time Crash. Before that, the only references to past incarnations (from 1963 to 1996) have been in the aforementioned episode "School Reunion" (in which the Doctor acknowledges having regenerated "half a dozen times" since last seeing Sarah Jane) and in drawings that the Doctor (who has temporarily become human to hide from the Family Of Blood) makes based on dreams of his other life in the 2007 episode " Human Nature". Seen on screen are the First, Fifth, Sixth, Seventh and Eighth Doctors, but a fuller view briefly available on the BBC website depicted all ten incarnations. However in the 2008 Christmas episode, The Next Doctor, the Tenth Doctor discovers an info stamp originally held by the Cybermen, which includes images of all his past selves. This is a clear affirmation of his past, and that the (then) current incarnation was indeed the Tenth. This was reaffirmed in the episode " The Eleventh Hour", when the Doctor asks the Atraxi whether this planet is protected. The Atraxi then shows 10 images, one of each Doctor from the first to the tenth, with the eleventh walking through the image of the tenth at the end. This is also confirmed in the episode " The Lodger", when the Doctor, explaining to Craig who and what he is, points at his face and says, "Eleventh."

Because each new Doctor is different from his previous incarnations, how their personalities interact varies when two or more different incarnations encounter each other. Time Crash featured Peter Davison returning as the Fifth Doctor. This event is explained as occurring due to the current Doctor having left his shields down when rebuilding the TARDIS following " Last of the Time Lords" and then accidentally crossing the Fifth Doctor's timeline, allowing the two TARDISes to merge. When the Tenth Doctor effortlessly averts the impending Belgium-sized hole in the Universe caused by this temporal anomaly, he reveals having known what to do because he saw himself do it as the Fifth Doctor and remembered. He goes on to tell the Fifth Doctor how fond he was of his incarnation and how he influences the current Doctor's personality. However, in their two meetings, the Second Doctor and Third Doctor had a degree of antagonism towards each other, with the patriarchal First Doctor critical of them both. During the Virgin New Adventures, the Seventh Doctor was occasionally at odds with his subconscious memory of his previous incarnation as his memory of his past self became increasingly associated with the Valeyard, his dark future self, but he eventually accepted his dark side and 'reformed' his memory of his former self, although it was never established how the two Doctors would interact if they had met in person.

On three occasions the Eleventh Doctor has actually encountered himself from a different point in his timeline: in The Big Bang, in the 2011 Comic Relief mini-episode Time, and in "Last Night", the fourth chapter of the five-part "mini-episode" Night and the Doctor, which debuted in the November 2011 DVD and Blu-ray box set release of the 2011 Series 6. In all three Steven Moffat-written stories, two versions of the Eleventh Doctor from different timelines meet and carry on brief conversations.

Reprising the role

On a few occasions, previous Doctors have returned to the role, guest-starring with the incumbent:

• William Hartnell and Patrick Troughton with Jon Pertwee in The Three Doctors. Originally Hartnell's role had been intended to be more extensive, but his health had deteriorated to the extent that he could only make a limited appearance. In the end, it turned out to be his last television role.
• Troughton and Pertwee with Peter Davison in The Five Doctors, the twentieth anniversary special, with another actor, Richard Hurndall, standing in for the late William Hartnell (the story began with a clip from The Dalek Invasion of Earth featuring Hartnell himself). Tom Baker declined to appear, feeling that the role came too soon after he had left the programme (a decision he later said he regretted) and the narrative was reworked to use clips from Shada, an intended six-part story from the Fourth Doctor's era that was never completed due to industrial action. A waxwork dummy of Baker from Madame Tussauds was used in the publicity photographs.
• Patrick Troughton with Colin Baker in The Two Doctors.
• Jon Pertwee, Tom Baker, Peter Davison, Colin Baker, and Sylvester McCoy – with rubber dummy heads standing in for the late William Hartnell and the late Patrick Troughton—in Dimensions in Time, a charity special in aid of Children in Need in 1993, the programme's 30th anniversary year. Except for the mannequin versions of Hartnell and Troughton, no two Doctors are shown on screen at the same time. (This story was a crossover with EastEnders).
• Peter Davison, Colin Baker and Sylvester McCoy in the first Big Finish audio adventure, The Sirens of Time.
• Peter Davison, Colin Baker, Sylvester McCoy and Paul McGann- the first three appearing initially as holograms using the Doctors' appearances and later as the Eighth Doctor's subconscious memory of his past selves), with Jon Pertwee posthumously joining them by virtue of an extant fan recording, in the audio adventure Zagreus, a fortieth anniversary special and the fiftieth release.
• Colin Baker and Sylvester McCoy in the second half of the audio Project Lazarus (Although the Sixth Doctor in this story is later revealed to be a clone of the Sixth Doctor created from DNA samples extracted during his previous visit rather than the actual Sixth Doctor).
• Peter Davison with David Tennant in the 2007 Children in Need special " Time Crash".
• Peter Davison, Colin Baker, Sylvester McCoy and Paul McGann in the Big Finish Audio The Four Doctors.

In addition to the above, Tom Baker, Davison, Colin Baker, McCoy, and McGann have reprised the role on many occasions since 1999 in audio dramas from Big Finish Productions.

Other actors have portrayed the character of the Doctor outside of the television series. For details on this see under Adaptations and other appearances in the main article and Doctor Who spin-offs.

For a list of all actors who have played the Doctor see List of actors who have played the Doctor.

Age

In early production documents, the Doctor was said to be 650 years old, although this was never stated on screen. By the time the Doctor did cite his age ("Let me see, in human terms, 400, yes, 450 years" in the serial The Tomb of the Cybermen; he also kept a 500-year diary), he had already regenerated to a younger form. The intention at that time was that regeneration had turned back the Doctor's clock, making him younger both in appearance and in biological age. Since the Doctor's age had never previously been given, 450 Earth years became a starting point onto which further years would be progressively added as the series continued and the character lived out his further incarnations.

The Third Doctor implied in Doctor Who and the Silurians and in The Mind of Evil that he had a lifetime that covered "several thousand years", though in either case he may have been referring to the breadth of time he had visited (or was able to visit) rather than actually lived through, or perhaps his own life expectancy. While the Doctor's age has never been a known quantity, these numbers are the most difficult to reconcile with the rest of the series.

By the time of The Brain of Morbius, the Fourth Doctor was stated to be 749 years old ("something like 750 years" in the prior Pyramids of Mars). In The Ribos Operation, Romana said the Doctor was 759 years old and had been piloting the TARDIS for 523 years, making him 236 when he first "borrowed" it. When the Doctor encounters his old friend Drax in The Armageddon Factor, Drax says it has been 450 years since their time together at the Academy, suggesting only that Drax was 450 years younger, but implying nothing about the Doctor's age, since it could have been a different amount of time for him. Drax also implies that the Doctor got his doctorate after that. In The Robots of Death, the Fourth Doctor states he is 750 years old.

In Revelation of the Daleks the Sixth Doctor said that he was "a 900-year-old Time Lord", and in Time and the Rani, the Seventh Doctor's age was 953, the same as villainous Time Lady the Rani (in both serials, the Doctor's age is stated in dialogue). In Remembrance of the Daleks the Seventh Doctor said that he had "900 years’ experience" rewiring alien equipment. At the beginning of the 1996 television movie, the Seventh Doctor was shown to have a 900-year diary in his TARDIS.

In the spin-off prose fiction, in the Fourth Doctor comic "The Time Witch" after the Doctor and Sharon cross through the split in time which they age four years which the Doctor says "I shall still think of myself as 743 ... or was it 730, I never can remember...", the Sixth Doctor celebrated his 991st birthday in the short story "Brief Encounter: A Wee Deoch an..?", written by Colin Baker himself, in Doctor Who Magazine Winter Special 1991: UNIT Exposed, while the Seventh Doctor celebrated his 1,000th birthday in Set Piece by Kate Orman, and the Eighth Doctor declared his age to be 1,012 in Vampire Science by Orman and Jonathan Blum. The Eighth Doctor spent nearly a century on Earth during a story arc spread over several novels, and also spent around 100 years asleep in The Sleep of Reason by Martin Day. Furthermore, in the Big Finish Productions audio play Orbis the Eighth Doctor says that he has spent 600 years living on the planet Orbis since the last play Vengeance of Morbius. In the same play he states that he lost count of his true age a long time previously and that he rounds it down and takes into account the different lengths of what is called a "year" in different locations (Although this implies that he might have been referring to 'years' based on Orbis's measurements rather than Earth's).

In the 2005 series, the Doctor's age is stated in publicity materials as 900 years, and in " Aliens of London", he says, "Nine hundred years of time and space, and I've never been slapped by someone's mother." Rose follows up by asking him if he is 900 years old, and he replies affirmatively, though it is unclear whether he is being disingenuous. He restates this as "Nine hundred years of phone box travel and it's the only thing left that surprises me", however, in " The Empty Child". In " Voyage of the Damned", the Tenth Doctor states that he is 903 years of age, the first time since Time and the Rani that an exact number has been stated in dialogue; previously, the Master also indicated the Doctor's age to be about 900 in the " The Sound of Drums"/" Last of the Time Lords" story arc.

How this figure is to be reconciled with the Doctor's age in the rest of the series and spin-off media is uncertain.

At the end of "The Sound of Drums", the Master ages the Doctor by 100 years using his laser screwdriver, leading the Doctor to assume an elderly appearance. In " Last of the Time Lords", the Master states to the population of Earth that the Doctor is nine hundred years old, and informs his subjects he will show them the Doctor's true form, suspending his ability to regenerate. The Master proceeds to age the Doctor further with his laser screwdriver, reducing him to a tiny, wrinkled being, subsequently imprisoned inside a bird cage until reverted to his current form with the help of Martha Jones, 15 satellites and the entire population of Earth. However as the resolution of that story is by means of a reversal of time, there is a suggestion that the events of that year never actually took place, and yet are present in the Doctor's memory.

In " The End of Time" the Doctor tells Wilfred Mott he is 906 years old. At the end of " Flesh and Stone", he tells Amy Pond that he is 907, whilst in " The Impossible Astronaut" he is 909, with a later Doctor also appearing who is 1103. In " The Doctor's Wife", the TARDIS while embodied as Idris says the Doctor has been travelling with her for 700 years – making him, if precise and if he had not also spent any extended periods away from the TARDIS along the way, at least 936 according to figures Romana provided in " The Ribos Operation". By the end of the series the Doctor has reached the age of 1103 at which we met him in The Impossible Astronaut. The next series ages the Doctor further, with A Town Called Mercy establishing that he is now approximately 1,200 years old.

Current producer Steven Moffat has stated that the Doctor simply does not know his own age, given the non-linear time-travelling nature of his life.

Romance

The very first episode of the television series established that Susan Foreman is the Doctor's granddaughter, but neither Susan nor the Doctor ever speak of her parents. In " Fear Her" (2006), the Doctor states that he was "a dad once", suggesting that he reproduced at some point. Furthermore, in " The Doctor's Daughter", his DNA was used to produce an "offspring".

The First Doctor did flirt with—and was accidentally engaged to—the character Cameca in The Aztecs; although this was part of a plot to get the TARDIS back, there was a hint of mutual attraction in Hartnell's performance (especially as he is ultimately unable to leave behind the love token she has given him). The fact that the TARDIS crew kept pressing forward in their travels was probably also a factor in preventing any romantic attachments.

As the series progressed and grew more popular among children, the Doctor was firmly established as an avuncular figure to his younger companions, the one exception being the Third Doctor's hurt reaction to his companion Jo Grant's leaving him for an idealistic scientific adventurer whom she describes as "a younger version" of the Doctor ( The Green Death). Jo kisses the Doctor on the cheek before she departs, the second time this form of affection had been shown on screen (the second Doctor having similarly kissed Zoe in The War Games).

Despite the press (and, occasionally, the production team) trying to play up the sexiness of some of the female companions or suggesting "hanky panky" in the TARDIS, the series reached the point where any suggestion of the Doctor as a sexual being was avoided altogether. One example was during City of Death, when the Fourth Doctor says to Countess Scarlioni, "You're a beautiful woman, probably". This rule held true even when the Doctor's apparent age was closer to those of his companions, or if there was on-screen chemistry between the actors, as there was between Fourth Doctor Tom Baker and his wife-to-be Lalla Ward's Romana II. In fact, a 1980 television commercial broadcast in Australia for Prime Computers showed Baker and Ward romancing each other, in character as the Doctor and Romana, with the commercial ending with The Doctor (prompted by the computer) proposing marriage. These commercials are not part of the regular series continuity.

In some of the voiceovers on Peter Davison's DVDs, the matter of physically expressed sexual attention is discussed. According to Peter Davison and Matthew Waterhouse ( Adric), John Nathan-Turner had very strict rules laid down about how the companions were allowed to physically interact with the Doctor, and Adric was allowed more physical contact with the Doctor than the female companions to downplay any potential romantic and/or sexual connotations.

The perception of the Doctor as essentially an asexual character, uninterested in romance, is why some portions of fandom reacted so strongly to the Eighth Doctor ( Paul McGann) kissing Dr. Grace Holloway in the 1996 television movie, breaking the series' long-standing taboo against the Doctor having any romantic involvement with his companions.

Modern-day romance

The current series has suggested that the Doctor has romantic feelings towards different people, but intentionally represses them. In "The Parting of the Ways" he kisses Rose Tyler to get the time vortex energy that was killing her back into the TARDIS, subsequently "killing" him and causing his next regeneration. In " School Reunion" the Doctor expresses dismay at having his companions age while he regenerates. In " The Next Doctor" he tells Jackson Lake that his companions "break [his] hearts". In " New Earth", Rose's body is temporarily inhabited by Cassandra, who kisses the Doctor romantically. This is one of the few scenes in the entire series where the Doctor is kissed romantically by his companion. He later was about to admit he loved Rose when they were having what was going to apparently be their final meeting, but was cut off before he could finish the sentence. The loss of Rose left him devastated and he was delighted with her later return, but left her on a parallel earth with a half-human clone of himself that could grow old with her.

Following his regeneration, the Eleventh Doctor expresses shock at the idea of his new companion Amy Pond kissing him by protesting that she was human. He also demonstrates a complex relationship with River Song, and they marry in " The Wedding of River Song". The 2005 series played with the idea of a romantic relationship between the Ninth Doctor and Rose Tyler, with many characters assuming they were a couple. Rose's boyfriend Mickey Smith clearly views the Doctor as a romantic rival for whom Rose has left him. Both showed flashes of jealousy when the other flirted with other characters. In the episode " The Doctor Dances", the Doctor admits to Rose that he "dances" (a euphemism established for sex in the episode). In" The Parting of the Ways", the Doctor's male companion Jack Harkness kisses both the Doctor and Rose in what he believes is a last goodbye. In the New Series Adventures novel Only Human by Gareth Roberts, Rose asks the Doctor how he would know that marrying for love is overrated, to which he cryptically answers, "Who says I don't? You ask the Lady Mary Wortley Montagu." In a December 2005 interview on BBC Four, actor David Tennant, who had just taken the role of the Tenth Doctor, described the relationship between the Doctor and Rose as "basically a love story without the shagging".

The Doctor's relationship with Rose intensifies after he regenerates into the Tenth Doctor. In the 2006 series, while possessed by Lady Cassandra, Rose kisses the Doctor. In " School Reunion", the arrival of the Doctor's previous companion Sarah Jane Smith and his reaction to seeing her again prompts jealousy and worry from Rose, and Sarah all but admits that she has long been in love with the Doctor. In the episode, " The Girl in the Fireplace" (written by Steven Moffat), the Tenth Doctor shares a passionate kiss with Madame de Pompadour, who takes him away to "dance", but how far the metaphor (coined in the episode " The Doctor Dances") is taken is not seen on screen. Rose does not seem to exhibit jealousy towards Madame de Pompadour. In the novel The Stone Rose, by Jacqueline Rayner, the Doctor kisses Rose after she saves him from being petrified, although it is described as "a kiss of gratitude and joy and unspeakable pleasure at being alive." In " The Impossible Planet" the Doctor and Rose share an awkward moment when they have to consider settling down in one time period and Rose suggests they do so together. She later plants a kiss for good luck on the Doctor's spacesuit prior to his descent into the pit. In " The Satan Pit" the Doctor, fearing for his life, tells someone "If you see Rose, tell her... tell her... oh, she knows". In " Doomsday", when the Doctor says his goodbye to Rose, she finally tells him that she loves him. He begins to reply, but the message is cut off, and he is unable to reciprocate; in the episode's audio commentary, executive producer Julie Gardner had stated that "he absolutely was going to say it...he was going to tell her he loved her." The reunion between the Doctor and Rose in 2008 episode " The Stolen Earth" is stated by executive producer Russell T Davies in Doctor Who Confidential to be a parody of romantic film conventions, because the heightened emotional content is abruptly interrupted by the Doctor being shot by a Dalek. In the next episode, " Journey's End", Rose challenges the Doctor to say what he didn't get to say before, to which he replies, "Does it need saying?". His half-human clone, however, does whisper it into Rose's ear, and the two of them kiss; Rose gets an emphatically romantic resolution to her romance storyline, as the clone-Doctor and Rose continue to live together on a parallel Earth. Gardner commented in Confidential that although the audience cannot hear, it is obvious that he is saying "I love you".

Throughout series three (2007), companion Martha Jones pines for the Doctor's affection ever since a kiss between them which was only used as a "genetic transfer" to distract their pursuers. She is distraught when, temporarily turned into a human in " Human Nature", the Doctor's human persona John Smith, falls in love with nurse Joan Redfern. She admits in " The Family of Blood" to Smith that "[the Doctor] is everything to me, and he doesn't even look at me, but I don't care, because I love him to bits, and I hope to God he won't remember me saying this". The Doctor tells Joan he is capable of everything that Smith was, but she rejects his attempt to establish a relationship with her as the Doctor. In the following episode, " Blink", he refers to being "rubbish at weddings, especially my own". Martha eventually quits as the Doctor's full-time companion in the season finale " Last of the Time Lords" because she is in love with the Doctor and he seems unable or unwilling to reciprocate; she received similar commiseration from Jack Harkness, who is also infatuated with him, in " The Sound of Drums". Subsequently in the 2008 series, the Doctor's friendship with Donna Noble is strengthened after the infatuations from with Martha and Rose, by the knowledge that she has no romantic interest in him whatsoever. Davies' last clear allusion to the Doctor's romantic capacity occurs at the beginning of his last episode as showrunner, The End of Time. The Tenth Doctor claims to have married "Good Queen Bess, and let me tell you, her nickname is no longer... (clears throat)", a reference to Elizabeth I of England's nickname "The Virgin Queen". The marriage, which calls "a mistake", explained Queen Elizabeth's reaction to seeing the Tenth Doctor in an earlier episode, " The Shakespeare Code". Subsequent episodes have alluded to this romantic, possibly sexual relationship.

Episodes written by Steven Moffat have continued to hint at the Doctor's romantic capacity; his stories during the Russell T Davies tenure as showrunner included the admission of a sex life in "The Doctor Dances" and the romance with Madame de Pompadour in "The Girl in the Fireplace", past marriages in "Blink", and the introduction of recurring character River Song in 2008 episodes " Silence in the Library"/" Forest of the Dead", who indicates she is a lover of the Doctor. In his tenure as showrunner (2010–present), the series continued to imply that the Doctor will have a relationship with, and perhaps marry, River Song. Additionally, Moffat has companion Amy Pond attempt to seduce the Doctor in " Flesh and Stone", and in " A Christmas Carol", the Eleventh Doctor finds himself accidentally engaged to film star Marilyn Monroe during a visit to 1950s Hollywood. The Doctor's past romantic relationship with Elizabeth I is also alluded to in Moffat episodes " The Beast Below" and " The Wedding of River Song", as well as in " Amy's Choice" by Simon Nye. In her 2010 appearances, River continues to hint at a relationship with the Doctor in her relative past and his relative future. In " The Big Bang", River suggests to the Doctor that she is married to him in his personal future. When River kisses the Doctor in " Day of the Moon", it becomes clear that while this is the Doctor's first kiss with her, it is to be her last with him, Implying that she shall soon be heading to The Library where she dies. In " A Good Man Goes to War", River is seen returning from a date with the future Doctor, and repeatedly calls the present-day Doctor "my love". In " Let's Kill Hitler", a young River Song compares herself to Mrs. Robinson and kisses the Doctor; the first time in an attempt to kill him, the second to save his life. Later she resolves to study archaeology so that she can encounter the Doctor again. Because she loves him, she refuses to shoot him in "The Wedding of River Song", creating an alternate timeline. In this world, the Doctor marries River in a very brief ceremony witnessed by Amy and Rory, so that he may allow time to return to normal and go to his death, while secretly disclosing to River that he will fake his death. Later, when Dorium comments that River is incarcerated in the Stormcage for "all her days", the Doctor responds "Her days, yes, her nights...well...that's between her and me".

Despite this, the Doctor's limited understanding of human romance and sexuality has been the subject of many jokes. For example, in "The Doctor's Wife", when he tells Amy and Rory that he is redoing the TARDIS's guest room, they suggest, "Perhaps not bunk beds this time," and he does not understand why they, a married couple, would not find bunk beds preferable to other furniture. In "A Good Man Goes to War", he is asked about Amy and Rory's sex life and refers to it as "private human stuff".

Spin-off passion

However, the spin-off media both before and after the television movie have toyed with the idea in various ways. In the 1995 Virgin New Adventures novel Human Nature by Paul Cornell, the Seventh Doctor takes on the human guise of "Dr John Smith" and has a romance with a teacher named Joan in 1914, albeit as a means to understand the human condition and with the Doctor's own memories as a Time Lord suppressed. The relationship ended when the Doctor was restored to normal, the Doctor admitting to Joan that he knows that Smith was fond of her but unable to reciprocate those feelings himself. This novel was adapted to the screen and comprised two episodes in the new series: "Human Nature" and "The Family of Blood", featuring the Tenth Doctor, with the Doctor implying that he retained Smith's feelings for Joan, although the more traumatic nature of the transformation may have impacted his feelings after he returned to normal.

The concluding chapter of The Dying Days, an Eighth Doctor novel by Lance Parkin, strongly implies intimacy occurring between the Doctor and Bernice Summerfield. In the Virgin novel Death and Diplomacy, by Dave Stone, the Seventh Doctor implies that he intentionally creates an image of asexuality to keep things simple. The Eighth Doctor elaborated on this idea in Interference- Book Two: Hour of the Geek, explaining that he had begun to experience an interest in romance and the idea of being close to someone in this body, but was reluctant to explore those feelings with his companions due to the amount of baggage a relationship with him would include.

In various novels—especially Lungbarrow – it is also established that Time Lords do not reproduce sexually, but emerge from genetic Looms fully grown, although in equivocal fashion the same book also hints that the Doctor's birth was an exception (unlike his cousins he has a belly button). This idea was brought to the forefront in the '96 movie, where the Doctor states he is "half-human, on [his] mother's side", suggesting he had a normal human birth, rather than a synthetic Gallifreyan one. Madame de Pompadour's reference to the Doctor's lonely childhood in "The Girl in the Fireplace" would also seem to contradict the Loom theory. The 2007 episode "The Sound of Drums" also directly contradicts this, with Gallifreyan children leaving for the academy when they reach the age of 8. This episode also shows a young Master. These mentions of early Time Lord childhood are repeated in the 2009/2010 " The End of Time". It should be noted however, that " The Infinity Doctors" and " Cold Fusion" suggest that certain "wombborn" families have survived in secret and that the Doctor and the Master are somehow from one of these families.

The classic series also made occasional references to the Doctor's childhood on Gallifrey ( The Time Monster, State of Decay and Black Orchid), and there had been the occasional reference to Gallifreyan children, also referred to as "Time Tots" by Romana in the audio adventure Zagreus and the incomplete 1979 serial Shada.

In the Big Finish Productions audio play Loups-Garoux, the Fifth Doctor reluctantly agrees to marry the werewolf Ileana De Santos and although he gets out of it later, as in Cameca's case, a degree of mutual attraction is present. In the plays involving the Eighth Doctor, his companion Charley confesses her romantic feelings for him in Zagreus, but although he admits he loves her back at the time, it is a highly dramatic moment and the relationship does not progress beyond the platonic.

The recurring novel and audio character Iris Wildthyme, created by Paul Magrs, is first introduced in the Short Trips story Old Flames, is a past romantic interest of the Doctor's who continues to flirt with him whenever they meet. In the audios Iris is played by Katy Manning, the actress who had formerly played Jo Grant during the Third Doctor's era. More of the Doctor's past relationships are explored in The Infinity Doctors and Cold Fusion.

The question of romance is sometimes sidestepped with plot devices in the spin-off media. In the 2001 BBC Books novel Father Time by Lance Parkin, the Doctor adopts an orphaned Gallifreyan-like alien called Miranda. It is implied in the book that Miranda is actually the daughter of the Doctor himself from the far future. Miranda returns in the novel Sometime Never... by Justin Richards, with her own daughter Zezanne. At that novel's end, a time-active being called Soul travels into the past accompanied by Zezanne, the two believing themselves to be the Doctor and Susan, respectively.

In The One Doctor, the Doctor kisses Sally-Anne Stubbins to bluff to the Sussyurat that he wasn't the Doctor but Banto Zane but this kiss showed no affection.

Discontinuities

While over the decades several revelations have been made about his background—that he is a Time Lord, that he is from Gallifrey, among others—the writers have often strived to retain some sense of mystery and to preserve the eternal question, "Doctor who?". This back-story was not rigidly planned from the beginning, but developed gradually (and somewhat haphazardly) over the years, the result of the work of many writers and producers.

This has led to continuity problems. Early histories of races such as the Daleks were rewritten, and so on. Series writer Paul Cornell, discussing continuity errors, opines that the modern series' " Time War" can explain away (or retcon) such discontinuities, giving the example of Earth's different destructions in The Ark (1966) and " The End of the World" (2005). Writer and Doctor Who executive producer Steven Moffat has gone further, arguing that "a television series which embraces both the ideas of parallel universes and the concept of changing time can't have a continuity error—it's impossible for Doctor Who to get it wrong, because we can just say 'he changed time'".

Some of the stories during the Seventh Doctor's tenure, part of the so-called " Cartmel Masterplan", were intended to deal with this issue by suggesting that much of what was believed about the Doctor was wrong and that he was a far more powerful and mysterious figure than previously thought. In both an untelevised scene in Remembrance of the Daleks and the subsequent Silver Nemesis it was implied that the Doctor was "more than just another Time Lord". The suspension of the series in 1989 means that none of these hints were ever resolved onscreen. The "Masterplan" was used as a guide for the Virgin New Adventures series of novels featuring the Seventh Doctor, and the revelations about the Doctor's origins were written into the novel Lungbarrow by Marc Platt. However, the canonicity of these novels, like all Doctor Who spin-offs, is open to interpretation.

Reception

UGO Networks listed the Doctor as one of their best heroes of all time.