On 21 March, Army Group H headquarters became Oberbefehlshaber Nordwest ("Army Command Northwest") commanded by Ernst Busch leaving the former Army Group H commander—Johannes Blaskowitz—to lead "Army Command Netherlands" (25th Army) cut off in the Netherlands. Busch—whose main unit was the German 1st Parachute Army —was to form the right wing of the German defenses. In the center of the front, defending the Ruhr, Kesselring had Field Marshal Walther Model commanding Army Group B (15th Army and 5th Panzer Army) and in the south Paul Hausser's Army Group G (7th Army, 1st Army and 19th Army).[22][23]