The brother of Valentinian I, Valens (c328-378 AD) was Roman Emperor of the East from 364 to 378. He defeated the invading Visigoths in 369 and campaigned against the Persian Empire from 372 to 376. The Visigoths were admitted into the empire in 377, but a year later they revolted, defeating and slaying Valens at Adrianopole.