On 24 October 1944, Priess succeeded Georg Keppler as commander of I SS Panzer Corps. He led this formation, as part of the 6th Panzer Army, in the failed "Ardennenoffensive", which was dubbed the Battle of Bulge. The objective of the offensive was to split the British and American line in half, so the Germans could then proceed to encircle and destroy four Allied armies, forcing the Western Allies to negotiate a peace treaty with the Axis Powers. Subordinated to I SS Panzer Corps was "Kampfgruppe" "Peiper", led by Joachim Peiper. Peiper's command was responsible for the Malmedy massacre, a war crime in which 84 American prisoners of war were murdered by their German captors near Malmedy, Belgium.