The Macedonian Dynasty saw expansion and the Byzantine Renaissance but also instability due to competition among nobles in the theme system.
The centuries-long gradual religious separation between the Eastern and Western Roman Empires culminated in the institutional separation known as the East-West Schism.
The Byzantine Empire had a long and tumultuous relationship with the Bulgar Empire to its north.
In 1071, the Byzantine Empire suffered two important defeats, against the Turks in the Battle of Manzikert and against the Normans in Bari, sometimes called the Double Disasters.
Tensions between Eastern and Western European powers boiled over during the Komnenian Dynasty; the West destroyed Constantinople and, with it, the Byzantine Empire.
Michael VIII recaptured Constantinople and restored the Byzantine Empire, giving rise to the last dynasty of the Empire and a brief time of cultural flourishing.
The restored Byzantine Empire converted to Catholicism to get aid from the West against the Ottoman Turks, but the Turks defeated them by conquering Constantinople, thereby causing the final collapse of the Byzantines.
The Byzantine Empire has had a lasting legacy in religion, architecture, art, literature, and law.