Jean Charles de, born on the 13th of February 1669 at Avignon, was a French military officer distinguished for his writings on tactics. His genius was roused by reading Caesar's Commentaries; and at the age of sixteen he entered the army contrary to his father's wish. By the Duke of Vendôme, who commanded in Italy in 1702, he was intrusted with part of his forces; and so well did he acquit himself, that he was honoured with the cross of St Louis, and received a pension of 400 livres. In the battle of Cassano, in August 1705, he lost, by a wound, the use of his left hand; and in 1706 he defended Modena against Prince Eugene, by whom he was taken prisoner some time after the battle of Blenheim. In 1711 he was appointed governor of Bourbourg, and in 1714 helped to defend Malta against the Turks. Soon after this he entered the service of Charles XII. of Sweden, and accompanied him in the invasion of Norway; but returned to France, where he served as colonel under the Duke of Berwick. In his later years he applied himself to the study of military art, and died at Avignon in 1752. His works are: Nouvelles Découvertes sur la Guerre, 1724, 12mo; Commentaires sur Polybe, 1753, 7 vols. 4to; and Fonctions et Devoirs d'un Officier de Cavalerie, 1733, 12mo.