What is its more common name?
Answer:
The Ardennes Offensive, which took place between December 16, 1944 and January 25, 1945, was a major German offensive launched towards the end of World War II through the forested Ardennes Mountains region of Belgium.
This German offensive was officially named the Ardennes-Alsace campaign by the U.S. Army, but it is known to the English-speaking general public simply as the Battle of the Bulge (the “bulge” was the initial incursion the Germans put into the Allies’ line of advance, as seen in maps presented in contemporary newspapers).