Foch, Ferdinand (1851–1929), a French army officer. As marshal of France he was supreme commander of the Allied armies at the close of World War I. Before the war, as commandant of the École Supérieure de Guerre (the War College), Foch had been the main architect of French military theory. National spirit, he believed, was as important as guns and men. “Victory is will,” he said. But he also stressed fundamentals of tactics and believed that plans should be flexible.

Foch was born at Tarbes, a town near the Spanish border. On his mother's side he descended from a family of soldiers. His father was a lawyer. After attending a Jesuit college at Saint-Étienne, Foch graduated from the École Polytechnique, a military and engineering college. His education was interrupted briefly by military service during the Franco-Prussian War (1870–71).

Foch was commissioned in the army in 1873 and became professor of military strategy at the École Supérieure de Guerre. In 1907 he was made the school's commandant. His lectures were published as Conduct of War (1897) and Principles of War (1899).

On the outbreak of World War I, Foch was first placed in command of an army corps in Lorraine. He was then given command of the 9th Army. In the first Battle of the Marne (1914), Foch's army was subjected to a fierce German assault. He launched a counterattack, stopping the Germans in his sector. His attack split the assault force in two and helped turn the tide of the battle in favor of the Allies.

Marshal FochMarshal Foch

Foch was the commander of French forces in battles at Ypres and Artois in 1915 and at the Somme in 1916. Because of the huge losses in these battles, Foch was relieved of his command. He was recalled to serve on General Henri Pétain's staff in 1917 and was named supreme commander in March, 1918. He was elevated to the rank of marshal soon after that.