JUSTINA, ROMAN EMPRESS. - Daughter of Justus, consularis of Picenum and a relative of Magnentius, whom she married while still a girl. Left a widow, around 370 she married Valentinian I, by whom she had 4 children. On the death of her husband (Nov. 373) she had her own son Valentinian II acclaimed emperor together with Gratian, and with him she resided at Sirmium until the death of Gratian (Aug. 383). Having come to Italy, she showed herself openly for what she was, an intriguing woman, directing her son's policy.
A declared supporter of Arianism, she engaged in a struggle against St. Ambrose, demanding that the bishop cede a basilica to the heretics. Ambrose refused, and G. attempted to have him arrested and driven into exile, but the people rose up in defense of their bishop. The Empress, enraged, responded with harsh repressions (385). Hardened ever more in her tyrannical high-handedness, in Jan. 386 she had an edict promulgated directed against St. Ambrose and the Catholics, by which the decisions of the Arian Council of Rimini were imposed and the death penalty was threatened against disturbers of religious peace. The following year, however, things changed radically: the usurper Maximus threatened to occupy Italy, posing as a defender of orthodoxy; G. was afraid and, to avert the danger, begged none other than St. Ambrose to go as ambassador to Maximus. The holy bishop, forgetting every injury, undertook the hard task. The mission had no success, and in 387 Maximus occupied Italy. G. together with her son Valentinian fled to Thessalonica, seeking asylum with Theodosius. She seems to have died in 388.