"Two major events in the ensuing reign of Constantine set the Near East on the course we have been pursuing through the mosaics. The first event was the emperor's conversion to Christianity and the subsequent establishment of Christianity as the state religion of the empire. The second was the removal of the central administration from Rome to the newly named Constantinople at Byzantium. The city on the Bosporus was soon to be recognized as a second Rome, or, in the words of the Cappadocian father Gregory of Nyssa, the 'newborn Rome.' By the early fifth century the city could simply be called Rome without further specification, and by the sixth century it is likely that, in the Near East at least, those who were not scholars or theologians did not even know what or where old Rome actually was."
G. W. Bowersock, Mosaics as history: the Near East from late antiquity to Islam, Revealing antiquity 16, ed. G. W. Bowersock (Cambridge, MA: Harvard University Press, 2006), 116, italics mine.