In the imperial era, it was customary for the emperor to serve as Pontifex Maximus. Although Constantine the Great reportedly converted to Christianity, and most of his successors were Christians, they continued to hold the office until the time of Gratian (375–383), who declined it, instead assuming the title of "Pontifex Inclytus", which was not associated with the former pagan state religion. The title of Pontifex Maximus thereafter fell into abeyance. After the sack of Constantinople and the end of the Eastern Roman Empire in the fifteenth century, the title was revived by the Popes, notwithstanding its pagan origins, and is now a part of the papacy's official titulature.