HIRSON, a town of northern France in the department of Aisne, 35 m. by rail N.E. of Laon, on the Oise. Pop. (1906) 8335. It occupies an important strategic position close to the point of intersection of several railway lines, and not far from the Belgian frontier. For its defence there are a permanent fort and two batteries, near the railway junction. The town carries on the manufacture of glass bottles, tiles, iron and tin goods, wool-spinning and brewing. HIRTIUS, AULUS (c. 90-43 B.C.), Roman historian and statesman. He was with Julius Caesar as legate in Gaul, but after the civil war broke out in 49 he seems to have remained in Rome to protect Caesar's interests. He was also a personal friend of Cicero. He was nominated with C. Vibius Pansa by Caesar for the consulship of 43; and after the dictator's assassination in March 44, he and his colleague supported the senatorial party against M. Antonius, with whom Hirtius had at first sided. The consuls set out for Mutina, where Antonius was besieging Decimus Brutus. On the 15th of April, Pansa was attacked by Antonius at Forum Gallorum, about 8 m. from Mutina, and lost his life in the engagement. Hirtius, however, compelled Antonius to retire on Mutina, where another battle took place on the 25th (or 27th) of April, in which Hirtius was slain. Of the continuations of Caesar's _Commentaries_--the eighth book of the Gallic war, the history of the Alexandrian, African and Spanish wars--the first is generally allowed to be by Hirtius; the Alexandrian war is perhaps by him (or Oppius); the last two are supposed to have been written at his request, by persons who had taken part in the events described, with a view to subsequent revision and incorporation in his proposed work on military commanders. The language of Hirtius is good, but his style is monotonous and lacks vigour. Hirtius and the other continuators of Caesar are discussed in M. Schanz, _Geschichte der romischen Literatur_, i.; also R. Schneider, _Bellum Africanum_ (1905). For the history of the period see under ANTONIUS; Cicero's _Letters_ (ed. Tyrrell and Purser); G. Boissier, _Cicero and his Friends_ (Eng. trans., 1897). HISHAM IBN AL-KALBI [Abu-l Mundhir Hisham ibn Mahommed ibn us-Sa'b ul-Kalb] (d. c. 819), Arabic historian, was born in Kufa, but spent much of his life in Bagdad. Like his father, on whose authority he relied largely, he collected information about the genealogies and history of the ancient Arabs. According to the _Fihrist_ (see NADIM) he wrote 140 works. As independent works they have almost entirely ceased to exist, but his account of the genealogies of the Arabs is continually quoted in the _Kitab ul-Aghani_.