Flavius Eusebius (Greek: Εὐσέβιος; died after 371) was a Roman Senator, who was the brother-in-law of the emperor Constantius II.
Probably through the influence of his sister Eusebia, the wife of Constantius II, Eusebius was appointed the governor of the province of Hellespontus in 355.
[2] After his term had completed, he went to Antioch where he was notified of his appointment as governor of Bithynia et Pontus, which he held in 356.
Eventually moving back to Antioch, it was here in 371 that Eusebius was accused of treason and put on trial during the reign of the emperor Valens.
[3] A Christian,[4] Eusebius was deeply admired by the teacher of rhetoric, Libanius, who described him as an excellent orator.