Flavius Gratianus, the son of Valentinian I and Severa, Gratian was given the rank of Augustus in 367 A.D., when only seven years of age. Following his father's death in 375, he became the sole ruler of the western division of the empire, though his four-year-old half-brother, Valentinian II, was also raised to the rank of Augustus at this time and was nominally associated with the government. After the catastrophe at Hadrianapolis, the eastern division of the empire also passed into Gratian's hands, but he found expedient to elevate his general Theodosius to be his colleague in the government of these provinces. In 383, Magnus Maximus, the commander of the roman armies in Britain was proclaimed Augustus by his troops and invades Gaul. Gratian, deserted by his own soldiers, fled in the direction of the alps, but was overtaken and murdered at Lugdunum in August of 383.