In December 1944, the German army launched a counterattack against Allied forces in western Europe. Its advance toward Antwerp, Belgium, created a "bulge" in the Allied lines. By June 1945, the bulge was contained and the Allied line was restored.
The Ardennes Offensive (called Unternehmen: Wacht am Rhein (Watch on the Rhine) by the German military Heeres Gruppe B), officially named the Battle of the Ardennes by the U.S. Army (and known to the general public as the Battle of the Bulge), started on December 16, 1944. Contrary to popular belief, it was not the last major German offensive on the Western Front during World War II; to the south Operation Nordwind began on 1 January.