Western Roman emperor from 425. He was the son of Constantius III and. Throughout the long regency of his mother (425-450) and the de facto military authority of Aetius,* Valentinian remained dependent and degenerate. Though Attila’s* famous march on Rome in 452 proved innocuous, the Western Empire declined greatly during his reign. Championing orthodoxy, Placidia’s first acts in Valentinian’s name in 425 were to restore church privileges revoked by the recently executed imperial usurper John, to exclude Jews and pagans from the bar and military rank, and to exile heretics and astrologers from the cities. Valentinian’s Novella 17 of 445 endowed the bishop of Rome, then Leo I, with authority over provincial churches in the West, including Greece—an important advantage in the pope’s rivalry with other patriarchs for universal supremacy. Valentinian was assassinated in 455.