	Early in 1945 Lange was appointed head of the SD and the SS in Poznań, Warthegau. Soon after he reached the city, Posen was surrounded by the Soviet Red Army and was declared a fortified city ("Festung"). Lange, who could not have any doubts about his destiny as a prisoner, directed the police under his command with fanaticism. He was wounded during the Battle of Poznań and the siege by Russian forces and was promoted SS-"Standartenführer" on 30 January 1945. At Hitler's behest, on 6 February 1945 he received the German Cross in gold. Lange may have died or committed suicide when the Red Army seized Poznań on 23 February 1945 after a last-ditch defence of the city by the remnants of the German garrison.