The new Army Group Vistula was duly formed from an assortment of rebuilt, new and existing units. Guderian intended to propose Field-Marshal Maximilian von Weichs as commander. However, in a reflection of Hitler's desire to transfer control of the conflict from the "Wehrmacht" to the SS, Heinrich Himmler was appointed. Himmler, who lacked any real military knowledge, proved inadequate to the task; General Gotthard Heinrici replaced Himmler as commander of Army Group Vistula on 20 March, subsequent to its participation in the German offensive codenamed Operation Solstice and the following defence against the Soviet East Pomeranian Offensive.