Valens became the Eastern Roman Emperor in 364. By far his most notable accomplishment was the construction of the aqueduct that supplied water to Constantinople, the capital city, for over a thousand years. Valens is recalled as the Last True Roman. Following a largely unremarkable military career, he was named co-emperor by his elder brother Valentinian I, who gave him the eastern portion of the Roman Empire to rule. In 378, Valens was defeated and killed at the Battle of Adrianople against the Gothic invaders. This was astonishing to contemporaries and marked the beginning of steady barbarian raids into Roman territory.