
The Byzantine Empire, also referred to as the Eastern Roman Empire or Byzantium, was the continuation of the Roman Empire in its eastern provinces during Late Antiquity and the Middle Ages, when its capital city was Constantinople. It survived the fragmentation and fall of the Western Roman Empire in the 5th century AD and continued to exist for an additional thousand years until the fall of Constantinople to the Ottoman Empire in 1453. its citizens continued to refer to their empire simply as the Roman Empire (Medieval Greek: Βασιλεία Ῥωμαίων, romanized: Basileía Rhōmaíōn) or Romania (Medieval Greek: Ῥωμανία), and to themselves as Romans (Medieval Greek: Ῥωμαῖοι, romanized: Rhōmaîoi) – a term which Greeks continued to use for themselves into Ottoman times. Several events from the 4th to 6th centuries mark the period of transition during which the Roman Empire's Greek East and Latin West diverged. The empire was delivered a mortal blow during the Fourth Crusade, when Constantinople was sacked in 1204 and the territories that the empire formerly governed were divided into competing Byzantine Greek and Latin realms. The fall of Constantinople to the Ottoman Empire in 1453 ended the Byzantine Empire.