The East–West Schism

After the death of Theodosius I in 395, the Roman Empire was divided into an Eastern half, based in Constantinople, and a Western, half based in Rome. Less than a century later, in 476, the last Western emperor Romulus Augustulus abdicated to a Germanic warlord who placed his own rule under that of the Eastern emperor. This act effectively ended the line of Western emperors and marked the end of the Western Empire. However, the Eastern portion (what historians call the Byzantine Empire) would continue for approximately another millennium.

The word Byzantine derives from Byzantium, the original name of Constantinople before Constantine moved the Roman imperial capital there in the fourth century. Despite this present-day appellation, those living within the borders of the Byzantine Empire did not call themselves Byzantine. They continued to call themselves Romans and, until the early seventh century, continued to speak Latin. Even Roman Catholicism remained the official religion of the Byzantine Empire until the eleventh century.

In an effort to recreate a unified Roman Empire, Justinian I (c. 527–565) was able to reconquer most of the Mediterranean coast, including North Africa, Rome, and southern Spain. This swath of territory remained in the Byzantine Empire for two centuries.

A significant cultural shift occurred in the early seventh century when Heraclius (c. 610–641) replaced Latin with Greek as the official language of the Empire. This caused religious tensions with the church in Rome that began in the fourth century and resulted in seven Ecumenical Councils over six hundred years. Finally, in 1054, the East-West Schism officially made the Eastern Orthodox Church, centred in Constantinople, its own separate entity from the Roman Catholic Church.

From the tenth century to the fifteenth, the empire experienced periods of peace and prosperity, as well as war and economic downturns. In the late eleventh century, the empire lost much of Asia Minor to the Turks, a temporary setback that foreshadowed the eventual weakening of Constantinople and the further loss of territory to the growing Ottoman Empire. In 1453, the Ottoman Turks invaded and captured Constantinople, bringing the Byzantine Empire to an end.