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 forces of the Allied Powers, primarily France and Britain, against the German Empire. The battle was characterized by trench warfare, as both sides dug in along the Aisne River in northern France. Despite initial advances, the battle resulted in a stalemate, with neither side able to secure a decisive victory. The conflict marked the beginning of a prolonged period of trench warfare on the Western Front, which would define much of the war.