Gomoarius.

Whilst a Military Tibune under the usurper Vetranio in December 350 he either betrayed his senior officer to the Emperor Constantius II, or, on another interpretation, he acted as co-between for an arrangement under which Vetranio was deposed peacefully and left to live out his life in retirement in Bithynia on a pension.

Whatever he did it certainly found favour with Constantius since by the time we next meet him in 360 he was Magister Equitum in Gaul under the Caesar Julian. Julian suspected, probably correctly, that the real reason he had been sent to Gaul was to keep a close eye on him. Ammianus Marcellinus refers to him at this time as “the old traitor Gomoarius”, but his treason appears to have consisted of nothing more than loyalty to Constantius.

In any event, Julian sent him back to Constantius. He next appears in command of a force of laeti trying to block the Succi Pass in the Haemus Mountains and thus prevent or delay Julian’s Eastward advance after his rebellion.

He seems to have retained his connection to the House of Constantine since he last appears in the records in 366 as one of the main generals supporting the usurper Procopius, who claimed support from the family of the dead Constantius II, against Valens. He appears to have been won over to Valens’ cause, however, after an emotional appeal by the old and respected general Arbitio. He is reported to have retired shortly afterwards, despite other claims that he was executed.

His background is not known, though his name certainly sounds Germanic.