376–378

The Battle of Adrianople and the Death of Emperor Valens

Fleeing the Hunnic invasion, the Visigoths received permission from Emperor Valens to settle in the empire as federates. Oppression by Roman officials led to a revolt. On August 9, 378, the Goths crushed the Roman army at Adrianople, and Valens himself died in the battle.

This ended the official Homoian (Arian) policy in the East. Valens's co-emperor Gratian sent the Spanish general Theodosius against the Goths. Theodosius eventually became emperor of the East and, more than anyone before him, sought to identify the Church with the empire.