Overview
Flavius Claudius Constantius Gallus (326–354) was a statesman and ruler in the eastern provinces of the Roman Empire from 351 to 354, as Caesar under emperor Constantius II, his cousin. A grandson of emperor Constantius Chlorus and empress Flavia Maximiana Theodora, and a son of Julius Constantius and Galla, he belonged to the Constantinian dynasty. Born during the reign of his uncle Constantine the Great, he was among the few male members of the imperial family to survive the purge that followed Constantine's death. Under Constantius II, Gallus served as deputy emperor, based in Antioch and married to Constantius' sister Constantina. He dealt with a Jewish revolt in the years 351-352. Gallus ultimately fell out of favor with Constantius and was executed, being replaced as Caesar by his younger half-brother Julian.
Family
Gallus was a son of Julius Constantius by his first wife Galla. Gallus' paternal grandparents were the emperor Constantius Chlorus and his second wife Flavia Maximiana Theodora. Julius Constantius was a paternal half-brother of the emperor Constantine I, which, in turn, meant Gallus was a half-first cousin of Constantine's sons, Constantine II, Constantius II and Constans. At some point prior to 331/2, Gallus' mother Galla seems to have died, as at that stage Julius Constantius was remarried to one Basilina and had had a son by her.
Gallus had three siblings: an elder sister, of unknown name, who was the first wife of Constantius II, an elder brother, also of unknown name, who died in the purges after the death of Constantine I, and a younger half-brother by his father's second marriage, named Flavius Claudius Iulianus, commonly known as Julian.
Youth
Gallus was born in Massa Veternensis, Italia, after his father had been recalled from exile. Gallus' father and his elder brother were amongst those killed during the purges that occurred in the imperial family after the death of Constantine I in 337. Gallus himself was one of the only imperial males – besides the three sons of Constantine I and Fausta – who were not killed; the others being Gallus' younger half-brother, Julian, and their cousin, Nepotianus, each of whom was very young at the time.
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