GRATIAN (Flavius Gratianus Augustus), Roman emperor 375–383, son of Valentinian I. by Severa, was born at Sirmium in Pannonia, on the 18th of April (or 23rd of May) 359. On the 24th of August 367 he received from his father the title of Augustus. On the death of Valentinian (17th of November 375) the troops in Pannonia proclaimed his infant son (by a second wife Justina) emperor under the title of Valentinian II. (q.v.). Gratian acquiesced in their choice; reserving for himself the administration of the Gallic provinces, he handed over Italy, Illyria and Africa to Valentinian and his mother, who fixed their residence at Milan. The division, however, was merely nominal, and the real authority remained in the hands of Gratian. The eastern portion of the empire was under the rule of his uncle Valens. In May 378 Gratian completely defeated the Lentienses, the southernmost branch of the Alamanni, at Argentaria, near the site of the modern Colmar. When Valens met his death fighting against the Goths near Adrianople on the 9th of August in the same year, the government of the eastern empire devolved upon Gratian, but feeling himself unable to resist unaided the incursions of the barbarians, he ceded it to Theodosius (January 379). With Theodosius he cleared the Balkans of barbarians. For some years Gratian governed the empire with energy and success, but gradually he sank into indolence, occupied himself chiefly with the pleasures of the chase, and became a tool in the hands of the Frankish general Merobaudes and bishop Ambrose. By taking into his personal service a body of Alani, and appearing in public in the dress of a Scythian warrior, he aroused the contempt and resentment of his Roman troops. A Roman named Maximus took advantage of this feeling to raise the standard of revolt in Britain and invaded Gaul with a large army, upon which Gratian, who was then in Paris, being deserted by his troops, fled to Lyons, where, through the treachery of the governor, he was delivered over to one of the rebel generals and assassinated on the 25th of August 383.
The reign of Gratian forms an important epoch in ecclesiastical history, since during that period orthodox Christianity for the first time became dominant throughout the empire. In dealing with pagans and heretics Gratian, who during his later years was greatly influenced by Ambrose, bishop of Milan, exhibited severity and injustice at variance with his usual character. He prohibited heathen worship at Rome; refused to wear the insignia of the pontifex maximus as unbefitting a Christian; removed the altar of Victory from the senate-house at Rome, in spite of the remonstrance of the pagan members of the senate, and confiscated its revenues; forbade legacies of real property to the Vestals; and abolished other privileges belonging to them and to the pontiffs. For his treatment of heretics see the church histories of the period.
Authorities.—Ammianus Marcellinus xxvii.-xxxi.; Aurelius Victor, Epit. 47; Zosimus iv. vi.; Ausonius (Gratian’s tutor), especially the Gratiarum actio pro consulatu; Symmachus x. epp. 2 and 61; Ambrose, De fide, prolegomena to Epistolae 11, 17, 21, Consolatio de obitu Valentiniani; H. Richter, Das weströmische Reich, besonders unter den Kaisern Gratian, Valentinian II. und Maximus (1865); A. de Broglie, L’Église et l’empire romain au IV e siècle (4th ed., 1882); H. Schiller, Geschichte der römischen Kaiserzeit, iii., iv. 31-33; Gibbon, Decline and Fall, ch. 27; R. Gumpoltsberger, Kaiser Gratian (Vienna, 1879); T. Hodgkin, Italy and her Invaders (Oxford, 1892), vol. i.; Tillemont, Hist. des empereurs, v.; J. Wordsworth in Smith’s Dictionary of Christian Biography. (J. H. F.)