 Gratian prudently acquiesced in their choice; reserving for himself the administration of the Gallic provinces, to command the forces responsible for the frontier, while handing over the peaceful Italy, Illyricum and Africa to Valentinian and his mother, who fixed their residence at Mediolanum.The division, however, was merely nominal, and the real authority even in those provinces remained in the hands of Gratian.Gratian, with the aid of his capable generals Mallobaudes, a king of the Franks, and Naniemus, completely defeated the Lentienses, the southernmost branch of the Alamanni, in May 378 at the Battle of Argentovaria.