Jovian – Roman emperor
Valentinian and Valens
Jovian was succeeded by another Eastern general, Valentinian, who was a Catholic. Valentinian soon decided that he would take control of the western part of the Roman Empire and leave the eastern part to his brother Valens. Valentinian’s capital was at Milan, while Valens, an Arian, lived in Constantinople. Donatist rebellions in Africa made the religious situation even more complicated.
Valentinian’s young son Gratian was engaged to Constantius II‘s daughter Constantia, to make the new emperors part of the old family, and in 367 AD he was made emperor as well, though he was only eight years old! Gratian’s teacher was the Christian Ausonius, but we know more about these people from Ammianus Marcellinus.
The Battle of Adrianople
All this time, the Roman army kept on fighting both the Germans and the Sassanids. In 378 AD the Romans lost an important battle at Adrianople (the city of Hadrian) in the Balkans, where Valens was killed fighting the Visigoths. The Visigoths pushed their way into the Roman Empire and settled down, and the Romans gave them refugee status and let them stay.
Theodosius, a young Catholic general of Spanish origin, and the son of another general, was chosen to succeed Valens. He ruled along with Gratian and his younger brother Valentinian II, the sons of Valentinian I.
Theodosius was able to regain the upper hand militarily, though mostly by making treaties with both the Visigoths and the Sassanids. In 383, a rebellious general named Maximus killed Gratian (who was 24). To make sure of his power, Theodosius married Gratian’s sister Galla, Valentinian’s daughter, in 387 (She was about 17). Then Maximus attacked Galla’s brother, Valentinian II, so Theodosius killed Maximus.
A non-Roman general named Arbogast rebelled at this news, killed Valentinian II in 392, and put a Roman friend of his, Eugenius, on the throne, but Theodosius defeated and killed them. Galla died in childbirth when she was about 24, in 394. By the time he died in 395 AD, Theodosius left a firmly Christian empire.
The Ancient Roman World, by Ronald Mellor (2004). Straight political history, For teens.
Classical Rome, by John Clare (1993). For kids, the whole political history from beginning to end.
The Romans: From Village to Empire, by Mary Boatwright, Daniel Gargola, and Richard Talbert (2004). Okay, it’s a little dry, but it is up to date and has all the facts you could want.
Theodosius: The Empire at Bay, by Stephen Williams and Gerard Friell (1998).