The history of medieval Christianity traces Christianity during the Middle Ages - the period after the Fall of Rome (c.476) until the Protestant Reformation (c.1517), considered the start of the modern era of Christianity.
Among the dioceses, five held special eminence: Rome, Constantinople, Jerusalem, Antioch, and Alexandria, generally referred to as the Pentarchy. The prestige of most of these sees depended in part on their apostolic founders, or in the case of Byzantium/Constantinople, that it was the new seat (New Rome) of the continuing Roman or Byzantine Empire. These bishops considered themselves the spiritual successors of those apostles.[1] In addition, all five cities were Early centers of Christianity.