 Later that year, Gratian's uncle Valens met his death in the Battle of Adrianople against a coalition of hostile Gothic and Hunnic tribes who had rebelled after being settled in Thrace by the eastern emperor.Valens refused to wait for Gratian, who had promised to march to his aid as soon as the Alemanni threat was contained; as a result, two-thirds of Valens men, to the number of 40,000 dead, fell in the battle along with the emperor and some of his top staff.By the time Gratian arrived in the east, the Gothic war had spiraled out of control; the provinces south of the Danube were daily being devastated by barbarians, and Roman authority as well as military prestige was all but annihilated.