Constantius Gallus - Caesar

Caesar

In 350, Magnentius had rebelled and killed the emperor Constans, claiming the purple. Constantius II prepared to move against the usurper, but needed a representative in the East, so he called Gallus at Sirmium, raised him to the rank of caesar (15 March 351), gave him the name Constantius, and strengthened the bonds with his cousin by allowing Gallus to marry his sister Constantina. Gallus and Constantina, who probably shared her brother's aim of controlling the young Caesar, set up residence in Antioch.

During his rule, Gallus had to deal with a Jewish rebellion in Judea/Palestine (see Jewish revolt against Gallus). The rebellion, possibly started before Gallus' elevation to Caesar, was crushed by Gallus' general, Ursicinus, who ordered all the rebels slain.

Gallus was saved from an assassination plot by a woman, who revealed that some members of her household were planning the murder. Some sources, among whom are Joannes Zonaras, claim that this plot had been organized by Magnentius in order to distract Constantius from Magnentius himself.

Some sources (Philostorgius) claim Gallus' generals won a campaign against the Sassanids. Others, basing their views on an almost-peaceful situation between Sassanids and Romans, dismiss this claim. In 354, Gallus sent the comes Orientis, Nebridius, against the Isaurians, who had been raiding the city of Seleucia on the Tigris.

As a consequence of the need to gather food for the troops of a Persian campaign or because of drought, the grain supply in Antioch decreased. In order to counter the higher price of grain, Gallus forced the passage of some laws regardless of the opinion of the Senate, thus alienating the support of the senatorial class of Antioch. Ammianus Marcellinus, a philo-senatorial writer, tells how the anger of the people of Antioch for the famine was diverted by Gallus towards the consularis Syriae Theophilus, who was killed by the mob.

Ammianus reports also that Gallus and Constantina started several trials for magic against wealthy people, ending in the execution of innocents and in the confiscation of their wealth. The same source claims that Gallus walked anonymously in Antioch by night, asking passersby for their opinion on their caesar, while Julian records the great amount of time spent by Gallus at the Hippodrome, probably to obtain popular support.

Doubting his cousin's loyalty, Constantius reduced the troops under Gallus, and sent the Praetorian Prefect Domitianus to Antioch to urge Gallus to go to Italy. Different sources tell different stories, but all agree that Gallus arrested Domitianus and the quaestor Montius Magnus who had come to his aid, and that the two officers were killed.

The arrest of Montius Magnus led to the discovery of what seems to be a plot to elevate an usurper against Gallus. The conspirators had the support of two tribuni fabricarum (officers of the weapons factories) who had promised the weapons for an uprising (Ammianus Marcellinus, 14.7.18), and probably of the troops in Mesopotamia, as well as of the rector of the province of Phoenice. All of those involved in the plot were sentenced to death.