GRATIAN (Flavius Gratianus)
- In 367 Valentian I made his eldest son, Gratian, then 7 years old, co-Emperor in the west. Valentinian's brother, Valens, remained emperor in the east.
- In 375 Valentian I died, and Gratian's half-brother, Flavius Valentinianus (Valentine II) , became his co-Emperor in the west.
- Gratian spent most of his reign in Gaul, defending the western provinces against Germanic tribes.
- In 378 he repulsed an Alamannic invasion of Gaul at Argentaria (near present-day Colmar, France) and drove the invaders back across the Rhine.
- When Valens was killed at the battle of Hadrianopolis in 378, Gratian appointed Theododius as emperor in the east.
- In 383 Magnus Maximus, his commander in Britain, rebelled against him and was proclaimed emperor by the army. Deserted by his troops, Gratian fled to Lugdunum (Lyon), where he was overtaken and killed.