The American Expeditionary Forces (A. E. F.) was a formation of the United States Armed Forces on the Western Front during World War I. The A. E. F. was established on July 5, 1917, in France under the command of then-Major General John J. Pershing. It fought alongside French Army, British Army, Canadian Army, New Zealand Army and Australian Army units against the Imperial German Army. A small number of A. E. F. troops also fought alongside Italian Army units in 1918 against the Austro-Hungarian Army. The A. E. F. helped the French Army on the Western Front during the Aisne Offensive (at the Battle of Château-Thierry and Battle of Belleau Wood) in the summer of 1918, and fought its major actions in the Battle of Saint-Mihiel and the Meuse-Argonne Offensive in the latter part of 1918.