In late 1944, the Nazi regime had sufficient resources for one last major offensive, and the choice was made to gamble everything on a push for the port city of Antwerp. Hitler had identified a weakness in the allied defense: American forces were stretched thin over the frontline in eastern Belgium and Luxembourg. Early morning on December 16, 1944, the German Ardennes Offensive took the allies by complete surprise.
Over the ensuing days and weeks, pockets of allied resistance succeeded in slowing the advance of the German army by just enough to allow reinforcements to arrive from the north and the south. As speed was absolutely essential to the German strategy, this delay proved decisive. The bulge in the the frontlines, from which this battle takes its name, never burst through to its objective, but stalled, then was gradually pushed back. Casualties were high: 80,000 on the allied side, including 19,000 killed, and 100,000 Germans killed, captured, or wounded.