In 1941, in the invasion of the Soviet Union, Geyr’s XXIV Panzer Corps was part of General Heinz Guderian’s Second Panzer Army, and consisted of all of Guderian's major tank units.[8] On 9 July 1941, he was awarded the Knight's Cross of the Iron Cross as General der Panzertruppe.[9] By early November 1941, Geyr's Panzer Corps commanded the 3rd, 4th, and 17th Panzer Divisions, the panzer regiment from the 18th Panzer Division, as well as the Infantry Regiment Großdeutschland, and spearheaded the advance of Army Group Centre during the Battle of Moscow.[8]