The Battle of the Ardennes was one of the opening battles of World War I. It took place from August 21-23, 1914, part of the Battle of the Frontiers. French commander-in-chief Joseph Joffre ordered an attack through the Ardennes forrest in support of the French invasion of Lorraine. The French forces consisting of the Third and Fourth Armies, expecting only light resistance ran into a German advance consisting of the German Fourth and Fifth Armies.
The initial engagement took place in a heavy fog and the Germans built defensive positions before heavy fighting commenced the second day. The French forces were badly routed by entrenched German machine guns, falling back to Verdun and Sedan.
The World War II battle in the same region was called the Battle of the Bulge.