The First Battle of the Aisne took place from September 12 to September 28, 1914, during World War I. It followed the First Battle of the Marne and involved the Allied Forces, primarily the British Expeditionary Force and the French Army, facing off against the German Army. The battle was characterized by trench warfare, marking a shift in military tactics. Despite initial advances, the Allies were unable to achieve a decisive victory, leading to a stalemate. The battle resulted in heavy casualties on both sides and set the stage for prolonged trench warfare along the Western Front for the remainder of the war.