From Rome to Byzantium, AD 363 to 565: The Transformation of Ancient Rome

These centuries witnessed a number of momentous changes in the character of the Roman empire. Most obviously, control of the west was lost during the fifth century, and although parts of the west were reconquered in the sixth century, the empire's centre of gravity had shifted irrevocably to the east, with its focal point now the city of Constantinople. Equally important was the increasing dominance of Christianity not only in religious life, but also in politics, society and culture.