Valentinian II (371 in Vienna, 392), son of Valentinian I, Roman Emperor from 375 to 392.
In 375, his brother, the Emperor Gratian being absent, the soldiers of Pannonia proclaimed him emperor when he was only four years old. Gratian accepted the partition of the empire and conceded Illyria to Valentinian II.
In 383, on the death of his brother Gratian, the empire had three emperors:Maximus in Trier, Valentinian II, under the tutelage of his mother Justine (Flavia Justina Augusta), in Milan, Theodosius I in Constantinople.
Justine encouraged Arianism and favored pagans like Symmachus or Pretextat.
In 387, Valentinian II was driven out by Maximus, who seized Rome and occupied Italy. Theodosius I hesitated to intervene. However, in love with Valentinian II's sister, Galla, whom he married, Theodosius I intervened against Maxime. While Valentinian II landed at the mouth of the Tiber, Theodosius I defeated Maximus and captured him in Aquileia.
Valentinian II returned to his capital Vienna where in 392 he was probably assassinated by a Frankish general, Arbogast, magister militum charged by Theodosius with the protection of the young Augustus. Some authors, however, relay the thesis of suicide. Arbogast proclaimed the pagan rhetorician Eugene emperor.