CONSTANS I., FLAVIUS JULIUS (d. 35o), emperor of the West, was the son of Constantine the Great and Fausta. Under his father he governed Western Illyricum, Italy and Africa, and at the division of the empire in 337 he received this share as emperor. His brother Constantine II. invaded him in 34o, but was defeated and killed. He was killed in the rebellion of Magnentius, in the Pyrenees, in 35o.
See Aurel. Vict., de Caes. xli. ; Cambridge Mediaeval History, vol. i.