During the Late Antiquity and Middle Ages periods, there was no Rome of the kind that ruled the Mediterranean for centuries and spawned the culture that produced twenty-eight public libraries in the urbs Roma. The empire had been divided then later re-united again under Constantine the Great who moved the capital of the Roman Empire in 330 AD to the city of Byzantium which was renamed Constantinople. The Roman intellectual culture that flourished in ancient times was undergoing a transformation as the academic world moved from laymen to Christian clergy. As the West crumbled, books and libraries flourished and flowed east toward the Byzantine Empire. There, four different types of libraries were established: imperial, patriarchal, monastic, and private. Each had its own purpose and, as a result, their survival varied.