Born in the city of Thessalonica, and of Macedonian descent, prior to AD 347 Eusebius was the Magister equitum et peditum in the east, probably under the emperor Constantius II. During his time as military commander, he intervened in Armenia, possibly to suppress the revolt of Bacour.
Probably a Christian, Eusebius had at least three children, Flavius Eusebius, Flavius Hypatius, both of whom held the consulship together in AD 359, and Eusebia, who married Emperor Constantius II after her father had died.
- Martindale, J. R.; Jones, A. H. M, The Prosopography of the Later Roman Empire, Vol. I AD 260–395, Cambridge University Press (1971)
- Martindale & Jones, pgs. 307-308
- Michael H. Dodgeon, Samuel N. C. Lieu, The Roman Eastern Frontier and the Persian Wars (AD 226-363): A Documentary History (1994), pg. 338
- Barnes, T. D., Christians and Pagans under Constantius in L'Eglise et L'Empire au IV Siecle (1989), pg. 317
- Martindale and Jones, pg. 308