GRATIA'NUS, .AUGUSTUS, eldest son of Valentinian I., by his first wife Severa, was born at Sirmium in Pannonia, on April 19, 359 A.D. While he was still nobilissimus puer (or heir-apparent), he was created consul, and in 367 was elevated by his father to the rank of Augustus at Ambiani, or Amiens, in Gaul. In the following year he accompanied his father in his expedition against the Alemanni, in order that he might be accustomed to warfare. On the death of Valentinian the troops elevated Gratianus to the throne, giving him at the same time as a colleague his half-brother Valentinian II. Gaul, Spain, and Britain fell to Gratianus's share; and as his brother was only four years old, Gratianus is supposed by many authorities to have been the monarch de facto of the rest of the western empire, fixing his residence at Treviri (now Treves). During the first part of his reign, a fierce warfare was carried on against the tribes who possessed the Danubian provinces and Illyricum; and he was on the point of marching into Thrace, to assist his uncle Valens against the Goths, when he was suddenly called upon to defend his dominions against the Lentienses, a tribe of the Alemanni. After the invaders had been defeated Gratianus advanced towards the eastern empire, but while on the way, he learned that his uncle Valens had been defeated and killed by the Goths near Adrianople (Aug., 378). The sovereignty of the eastern empire then
devolved upon Gratianus, but feeling his inadequacy to the task of ruling the whole empire, he recalled Theodosius (q.v.) from Spain, and appointed him his colleague on Jan. 19, 379. Gratianus possessed some admirable virtues: he was pious, chaste, and •temperate; his understanding was well cultivated, although not strong, and his eloquence attractive. But his character was too yielding and pliant, and lie was conse quently often led to the commission of gross acts of cruelty and tyranny, utterly foreign to his nature. His persecution of the pagans, and afterwards of heretic Christians, made him a great favorite with orthodox ecclesiastics, but rather alienated the affections of his subjects generally, while his fondness for frivolous amusements, and unworthy associates, excited the contempt of the army, so that when Maximus was proclaimed emperor by the legions in Britain, crowds of the disaffected flocked to his standard. Gratianus was defeated by him near Paris, and afterwards fled to Lyons, where he was overtaken and killed by Andragathius, whom Maximus had sent in pursuit of him, on Aug. 25, 383.