Gratian was the son of Emperor
Valentinian I by
Marina Severa, and was born at
Sirmium in
Pannonia. He was named after his grandfather
Gratian the Elder. Gratian was first married to Constantia, daughter of
Constantius II. His second wife was Laeta. Both marriages remained childless.
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
Mediolanum. 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 the
Battle of Argentovaria, near the site of the modern
Colmar. Later that year, Valens met his death in the
Battle of Adrianopole on
August 9. Valens refused to wait for Gratian and his army to arrive and assist in defeating the host of
Goths, Alans and
Huns; as a result, two-thirds of the eastern Roman army were killed as well.
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 then cleared the
Balkans of
barbarians in the
Gothic War (376-382).
For some years Gratian governed the empire with energy and success but gradually sank into indolence, occupying himself chiefly with the pleasures of the chase, and became a tool in the hands of the
Frankish general
Merobaudes and bishop
Ambrose of
Milan.
By taking into his personal service a body of Alans, and appearing in public in the dress of a
Scythian warrior, after the disaster of the Battle of Adrianopole, 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
Lyon. There, through the treachery of the governor, Gratian was delivered over to one of the rebel generals, Andragathius, and assassinated on
August 25, 383.
