The Battle of the Bulge, also known as the Ardennes Counteroffensive, was a final and desperate attempt by Adolph Hitler to force a negotiated peace treaty with the Allied Forces on the Western Front. A weak spot in the Allied lines in the Ardennes Forest close to the German border was struck by about 250,000 German troops in a surprise attack on December 16, 1944, initiating what was to become the bloodiest battle in United States military history. The battle, which lasted until January 25, 1945, saw combined military casualties estimated to be as high as 190,000, but the Allied victory resulted in a fatal blow to the German forces which led, ultimately, to the fall of Berlin and Germany's unconditional surrender on May 8, 1945.
Allied overconfidence combined with poor reconnaissance and a preoccupation with offensive strategies gave the German forces the significant advantage of the element of surprise. The counteroffensive enabled German troops to achieve a 50 to 80 mile westward bulge into the Allied front lines that gave the battle the name by which it is most commonly known. The American forces, after heavy and snowbound fighting on rough terrain and in freezing temperatures, were able to regroup and launch a counterattack that pushed the Allied front lines back to the positions held before the battle began. After the battle, Germany's reserve forces were depleted, its air force was shattered, and what was left of the German army was in retreat.