World War II - Battle of the Bulge
The Battle of the Bulge 16 December 1944 – 25 January 1945 was a major German offensive campaign launched through the densely forested Ardennes region of Wallonia in Belgium, France, and Luxembourg on the Western Front towards the end of World War II in the European theatre.
The surprise attack caught the Allied forces completely off guard. American forces bore the brunt of the attack and incurred their highest casualties for any operation during the war. The battle also severely depleted Germany's armoured forces on the Western Front, and they were largely unable to replace them. German personnel, and later Luftwaffe aircraft (in the concluding stages of the engagement), also sustained heavy losses.