Adolf Hitler's armies were being pushed back to Germany on all fronts. Hitler's goal for the 'Battle of the Bulge" was to Split the Allies and push them back capture the town of Antwerp and negotiate a peace treaty.
Hence the fact that Hitler's army was losing everywhere he was taking in heavy casualties and was forced to scavenge the rest of his soldiers. Hitler was able to gather over two hundred thousand men.
The "Battle of the Bulge" took place in the Ardennes Region of Belgium and Luxembourg, where that allied presence was weakest. The German army waited for the weather to be right, on December 16 snow and fog presented the opportunity to invade.
The Battle of the Bulge is remembered as the last German offensive. Casualties on both sides were very heavy.
The reason the Battle of the Bulge is called the "bulge" is because when American troops first saw the German Army stacked up along the Ardennes they accounted " It looks like a giant bulge of Krauts". The Bulge would have allowed the German Army to create a peace treaty but really most of Hitler's army was killed and it allowed the Allies to push farther towards Germany.