 He founded the Valentinian Dynasty, with his sons Gratian and Valentinian II succeeding him in the western half of the empire.Valentinian was born in 321 at Cibalae in southern Pannonia (now Vinkovci in Croatia) into an Illyro-Roman family.Valentinian and his younger brother Valens were the sons of Gratianus Major, a prominent commander during the reigns of emperors Constantine I and Constans I.