a Roman historian of the fourth century, was born in the city of Antioch, in Syria. Having served several years in the early part of his life in the army, he was afterwards promoted to the honourable station of *protector domesticus*. In the year 350 he entered the service of Constantius, the emperor of the East, and under the command of Ursicinus, a general of the horse, he served during several expeditions. According to his own modest relation, it appears that he acquired considerable military fame, and that he deserved well of his sovereign. He attended the emperor Julian in his expedition into Persia, but history is silent respecting his having obtained any higher military promotion than that which has already been mentioned. He was either in the city or the vicinity of Antioch when the conspiracy of Theodorus was discovered, in the reign of Valens, and was an eye-witness of the severe torments to which many persons were exposed by the emperor on that account.

But his lasting reputation was not to be acquired from military exertions. He left the army and retired to Rome, where he employed his time and talents in writing a history of that empire, comprising a period of 282 years. Though a Greek by birth, he wrote in the Latin language; but, according to the remark of Vossius, his Latin shows that he was a Greek, and also a soldier. His history extended from the accession of Nerva to the death of Valens; and the work was originally divided into thirty-one books. Of these the first thirteen have perished, and the eighteen which remain commence with the seventeenth year of the reign of Constantius, and terminate at the year 378. But there are several facts mentioned in the history which prove that the author was alive in the year 380. Of this number are the accession of Theodosius to the eastern empire, the character of Gratian, and the consulate of Neotherius. Some have reckoned the style harsh and redundant, but this may easily be excused, from his education and military life; and the valuable information communicated abundantly compensates for that defect. Candour and impartiality are leading features in his history. Gibbon appears to have Ammianus fairly estimated his character, when he says that he is "an accurate and faithful guide, who composed the history of his own times without indulging the prejudices and passions which usually affect the mind of a contemporary."

There is a difference of opinion as to whether he was a Christian or a pagan. But the respectful manner in which he speaks of pagan deities, and of the advantage of heathen auguries to foretell future events, renders it abundantly evident that he was a heathen. The favourable account which he gives of the religion, manners, and fortitude of Christians, is the result of his candour and impartiality as an historian. The work of Ammianus has passed through several editions, of which the best are the Leyden edition of 1693, and those of Leipsic, published in 1773 and 1808.