During the postclassical period, two major civilizations formed in Europe. The Byzantine Empire was one of them. It was in western Asia and southeastern Europe and expanded into eastern Europe. The Byzantine maintained very high levels of political, economic, and cultural life between 500 and 1450 C.E.
Historians generally refer to the Eastern Roman Empire after 476 as the Byzantine Empire. But this is an arbitrary distinction invented for the convenience of historians. People in the Byzantine Empire continued to think of themselves as Romans, and their empire as the Roman Empire, for centuries after 476. The Byzantine Empire would endure as a Christian empire for another 1000 years until it was finally overrun by the Ottomans in 1453.