Gratian , (Augustus Gratianus), emperor of Rome, born in Pannonia in 359, slain at Lugdunum (Lyons) in 383. His father, Valen-tinian I., bestowed upon him the title of Augustus in his childhood, but when he died in 375 the officers of the army compelled Gratian to give his half brother Valentinian II., then a young child, a share in the western empire, the East being in the hands of his uncle Valens. Gratian received Gaul, Spain, and Britain, and reigned over Italy, Illvricum, and Africa as guardian of his brother. Great severity marked the beginning of his reign. When the East was attacked by the Goths, Gratian was delayed in aiding his uncle by another incursion of barbarians from the north; and when he finally marched to his rescue, he received the news of his defeat and death (378), which made him the ruler of both parts of the empire. In the next year he ceded the East to the younger Theodosius. Several wars with barbarous tribes on the Rhine and Danube were successfully terminated, and Gratian, who is praised by both Christian and pagan historians as just, moderate, and virtuous, now enjoyed a few years of repose at his residence in Milan, where he became the friend of St. Ambrose. By the confiscation of the property of the temples and the abolition of the privileges of the priests, he greatly contributed to the downfall of paganism.
A military rebellion, which broke out in Britain under Maximus, and spread to Gaul, deprived him of his throne and life.