The Battle of the Bulge, also known as the Ardennes Counteroffensive, was a major German offensive campaign on the Western Front during World War II which took place from 16 December 1944 to 25 January 1945. It was launched through the densely forested Ardennes region between Belgium and Luxembourg towards the end of the war in Europe. The offensive was intended to stop Allied use of the Belgian port of Antwerp and to split the Allied lines, allowing the Germans to encircle and destroy the four Allied forces and cause the Allies to negotiate a peace treaty in the Axis powers' favor. The Battle of the Bulge remains among the most important battles of the war, along with Stalingrad, Operation Overlord, Monte Cassino, and Midway. It marked the last major offensive attempted by the Axis Powers in Europe. After their defeat, Germany would retreat for the remainder of the war.
The Germans achieved a total surprise attack on the morning of 16 December 1944, due to a combination of Allied overconfidence, preoccupation with Allied offensive plans, and poor aerial reconnaissance due to bad weather.