"The Byzantine Empire was the predominantly Greek-speaking continuation of the Roman Empire during Late Antiquity and the Middle Ages. It had its capital in the city of Constantinople, also known as Byzantium. Initially the eastern half of the Roman Empire (often called the Eastern Roman Empire in this context), it survived the 5th century fragmentation and collapse of the Western Roman Empire and continued to thrive, existing for an additional thousand years until it fell to the Ottoman Turks in 1453."--Wikipedia.