With war looming, Hitler needed experienced commanders, and he recalled Kluge from retirement in October 1938 and gave him command of the newly created 6th Army Group, headquartered at Hanover. Later, the unit was redesignated as the Fourth Army. Kluge led Fourth Army during the invasion of Poland in September 1939. Proving himself an innovative commander in that campaign, he won Hitler's admiration and promotion to colonel general. Kluge led Fourth Army against France and the Low Countries in May 1940. Raised to field marshal in July, he went on to command Fourth Army in the invasion of the Soviet Union in June 1941 and Army Group Center from December 1941 to October 1943, again proving himself an effective commander.
Injured in a car accident in October 1943, Kluge went on prolonged leave during his recuperation. In July 1944, he replaced Field Marshal Karl Gerd von Rundstedt as commander in chief, West, and commander of Army Group B in Normandy. Kluge disliked the Nazis but was pleased with the territorial acquisitions made under Hitler. He was aware of the plot to assassinate the Führer, but he wavered in his support and finally declined to participate. He also failed to report it. Following the bomb attempt on Hitler's life on 20 July 1944, he came under increased Gestapo suspicion.
Kluge led the German counterattack at Avranches in August, but on its failure, he was relieved of command, on 17 August 1944, by Field Marshal Walther Model. He wrote to Hitler, urging him to make peace and end the suffering for the German people. Aware that he would be implicated in the conspiracy against Hitler and depressed by the military situation, Kluge committed suicide at Valmy, France, on 19 August 1944.
Spencer C. Tucker
Lamb, Richard. "Field-Marshal Günther von Kluge." In Correlli Barnett, ed., Hitler's Generals, 395–409. New York: Grove Weidenfeld, 1989.; Mitcham, Samuel W., Jr. Hitler's Field Marshals and Their Battles. Chelsea, MI: Scarborough House, 1988.