Gaius Asinius Pollio, already mentioned as a critic and tragedian, was also the author of the most important historical work of the Augustan age after Livy's. This was a _History of the Civil Wars,_ in seventeen books, from the formation of the first triumvirate in 60 B.C. to the battle of Philippi. Though Pollio was a practised rhetorician, his narrative style was simple and austere. The fine ode addressed to him by Horace during the composition of this history seems to hint that in Horace's opinion-- or perhaps, rather, in that of Horace's masters--Pollio would find a truer field for his great literary ability in tragedy. But apart from its artistic quality, the work of Pollio was of the utmost value as giving the view held of the Civil wars by a trained administrator of the highest rank. It was one of the main sources used by Appian and Plutarch, and its almost total loss is matter of deep regret. An author of less eminence, and belonging rather to the class of encyclopedists than of historians, is Pompeius Trogus, the descendant of a family of Narbonese Gaul, which had for two generations enjoyed the Roman citizenship. Besides works on zoology and botany, translated or adapted from the Greek of Aristotle and Theophrastus, Trogus wrote an important _History of the World_, exclusive of the Roman Empire, which served as, and may have been designed to be, a complement to that of Livy. The original work, which extended to forty-four books, is not extant; but an abridgment, which was executed in the age of the Antonines by one Marcus Junianus Justinus, and has fortunately escaped the fate which overtook the abridgment of Livy made about the same time, preserves the main outlines and much of the actual form of the original. Justin, whose individual talent was but small, had the good sense to leave the diction of his original as far as possible unaltered. The pure and vivacious style, and the evident care and research which Trogus himself, or the Greek historians whom he follows, had bestowed on the material, make the work one of very considerable value. Its title, _Historiae Philippicae_, is borrowed from that of a history conceived on a somewhat similar plan by Theopompus, the pupil of Isocrates, in or after the reign of Alexander the Great; and it followed Theopompus in making the Macedonian Empire the core round which the history of the various countries included in or bordering upon it was arranged.