The Battle of the Milvian Bridge (1520–24) by Giulio Romano. Roman politics after the Emperor Diocletian abdicated in AD 305 was confusingly complicated as emperors and deputy emperors of the West and of the East contended for power. The Battle of the Milvian Bridge was one of a succession of victories that in AD 324 made Constantine master of the entire Roman Empire, but it is most famous for its link with his conversion to Christia...