For the 12th century canon lawyer, see Gratian (jurist).

Flavius Gratianus Augustus (April 18/May 23, 359 - August 25, 383), known as Gratian, was a Western Roman Emperor from 375 to 383. He was the son of Valentinian I by Severa and was born at Sirmium in Pannonia.

On August 4, 367 he received from his father the title of Augustus. On the death of Valentinian (November 17, 375), the troops in Pannonia proclaimed his infant son (by a second wife Justina) emperor under the title of Valentinian II.

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 Roman 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. Later that year, Valens met his death in the Battle of Adrianople on August 9.

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 promoted Theodosius I on January 19, 379 to govern that portion of the empire. Gratianus and 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 lands of the Frankish general Merobaudes and bishop Ambrose of Milan.

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 general named Magnus Maximus took advantage of this feeling to raise the standard of revolt in Britain and invaded Gaul with a large army. Gratian, who was then in Paris, being deserted by his troops, fled to Lyons. There, through the treachery of the governor, Gratian was delivered over to one of the rebel generals and assassinated on August 25, 383.

The reign of Gratian forms an important epoch in ecclesiastical listory, since during that period Orthodox Christianity for the first time became dominant throughout the empire. Under the influence of Ambrosius, Gratian prohibited pagan 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, despite protests 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.

This article incorporates text from the public domain 1911 Encyclopædia Britannica.