Roman Forum, Rome — completed 312 CE The last and largest civic basilica of imperial Rome, also known as the Basilica Nova. Begun by Maxentius and completed under Constantine, it dominated the Forum with a scale closer to the great imperial baths than to its basilica predecessors — groin vaults rising thirty-five metres above the nave, a single span unmatched in Roman civic architecture. Studied at length by Bramante, Raphael, and Michelangelo, it shaped the architectural imagination of the Renaissance and, through it, the design of St. Peter's. Architect unknown.