A year after the Council Constantine dedicated, amid the desolation of Byzantium, a new city which he termed Nova Roma, and which posterity called by his name. In 330 he turned his back upon both Rome and Nicomedia, and made Constantinople his capital. There he surrounded himself with the impressive pomp of an Oriental court, feeling that its psychological influence upon army and people would make its expensive pageantry a subtle economy in government. He protected the army with able diplomacy and arms, tempered despotism with humane decrees, and lent his aid to letters and the arts. He encouraged the schools at Athens, and founded at Constantinople a new university where state-paid professors taught Greek and Latin, literature and philosophy, rhetoric and law, and trained officials for the Empire. He confirmed and extended the privileges of physicians and teachers in all provinces. Provincial governors were instructed to establish schools of architecture, and to draw students to them with divers privileges and rewards. Artists were exempted from civic obligations, so that they might have time to learn their art thoroughly and transmit it to their sons. The art treasures of the Empire were drawn upon to make Constantinople an elegant capital.

In Rome the architectural works of this period were inaugurated by Maxentius. He began (306), and Constantine finished, an immense basilica that marked the climax of classical architecture in the West. Adapting the structure of the great baths, this edifice covered an area 330 by 250 feet. Its central hall, 114 by 82 feet, was roofed by three cross vaults of concrete 120 feet high, partly supported by eight broad piers faced with fluted Corinthian columns sixty feet tall. Its pavement was of colored marble; its bays were peopled with statuary; and the walls of these bays were prolonged above their roofs to serve as elevated buttresses for the central vaults. Gothic and Renaissance architects found much instruction in these vaults and buttresses. Bramante, designing St. Peter’s, planned to “raise the Pantheon over the Basilica of Constantine”- i.e., to crown a spacious nave with a massive dome.