CASTELNAU, EDOUARD DE CURIERES DE (1851 ), French soldier, was born at Saint-Affrique, Aveyron, Dec. 24, 1851, third son of the Marquis de Curieres de Castelnau. He entered the military school of St. Cyr, near Versailles, in 1869; and during the Franco-German War took part in the Loire cam paign. Captain in 1876 and commandant in 1889, he was ap pointed by Gen. de Miribel in 1893 to a post in the chief depart ment of the general staff ; later, as head of the department he built up the vast system of French mobilization. In 1910 he be came general of division, and in June 1911 assistant to the chief of the general staff. On the outbreak of the World War he com manded the II. Army in Lorraine. After the French offensive had failed at Morhange in Aug. 1914, General Castelnau in turn suc cessfully repulsed the Germans at the Trouee de Charmes and the heights of the Grand Couronne. On Sept. 18 the II. Army was moved to the west between the Somme and the Oise in the abortive attempt to outflank the German armies—known as the "race to the sea." On June 13, 1915, Gen. Castelnau took command of the group of four armies which constituted the French centre, and directed the September offensive in Champagne. In the following Decem ber he became chief of the general staff under General Joffre. He was next sent to Salonika on a tour of inspection, returning by way of Athens and Rome. Three days after the opening of the Ger man attack at Verdun on Feb. 21, 1916, Castelnau was sent there on an emergency mission, with full powers, and appreciating the danger, gave orders that the right bank of the Meuse should be held at all cost ; he returned to Chantilly only when the position was secure. On the appointment of Nivelle in place of Joffre, Castelnau was sent on a mission to St. Petersburg in Jan. 1917. On his return he was given command of the group of armies in the east with a view to directing the large-scale operations which were anticipated in Nov. and which the Armistice happily fore stalled. After the war General Castelnau entered the Chamber as deputy for Aveyron ; he acted as president of the army committee, and allied himself to the group known as the Entente democrati que et sociale. See Victor Giraud, Castelnau (1921).