Ammianus Marcellinus

Ammianus Marcellinus was a fourth-century Roman soldier and historian. His surviving history describes the later Roman Empire from the reign of Constantius II to the death of Valens, including court politics, frontier warfare and the Persian campaigns of Julian.

Ammianus began his career as an officer among the protectores domestici and served under the general Ursicinus in both the eastern provinces and Gaul. He witnessed major episodes of the fourth-century military crisis at first hand and later accompanied Julian’s Persian expedition of 363 and the difficult Roman retreat that followed the emperor’s death. Settling eventually in Rome, Ammianus drew on this military experience when composing his history, whose surviving books are among the most important contemporary accounts of the later Roman Empire.

The Later Roman Empire is not a later biography of Ammianus Marcellinus but the surviving portion of his own history, and it is the principal reason his voice remains so important. Writing with the experience of a former soldier, Ammianus describes Constantius II, Julian’s Persian expedition, frontier warfare and the reigns of Valentinian and Valens. His mixture of eyewitness testimony, political judgement and military detail makes the work one of the essential contemporary sources for the fourth-century empire.