The IX Armeekorps was formed in 1934 as the Heeresdienststelle Kassel and redesignated in 1935.

Commanders

General der Artillerie Friedrich Dollmann (01 Oct 1934 - 25 Aug 1939)
General der Infanterie Hermann Geyer (25 Aug 1939 - 31 Dec 1941)
Generalleutnant Martin Dehmel (25 Sep 1941 - 00 Oct 1941) m.d.st.F.b.
General der Infanterie Hermann Geyer (00 Oct 1941 - 31 Dec 1941)
General der Infanterie Hans Schmidt (01 Jan 1942 - 15 Oct 1943)
General der Infanterie Heinrich Clößner (15 Oct 1943 - 03 Dec 1943) m.d.F.b.
General der Artillerie Rolf Wuthmann (03 Dec 1943 - 20 Apr 1945)
Generalleutnant Dr. Hermann Hohn (20 Apr 1945 - 8 May 1945) m.d.F.b.

Area of operations

Germany (Sep 1939 - May 1940)
France (May 1940 - June 1941)
Eastern front, central sector (June 1941 - Dec 1944)
East Prussia & northern Germany (Jan 1945 - May 1945)

Notable members

Hans Otfried von Linstow (Active in the resistance against Hitler and executed after the failure of the July 20 Plot)

Sd.Kfz. 231 during an exercise of IX Armeekorps in 1935 in Bayrischen Ostmark

(Courtesy of Bundesarchiv/Wikimedia, licensed under Creative Commons Attribution ShareAlike 3.0 Germany)

Sd.Kfz. 231 and Sd.Kfz. 232 on parade during an exercise of IX Armeekorps in September 1936 near Fritzlar

(Courtesy of Bundesarchiv/Wikimedia, licensed under Creative Commons Attribution ShareAlike 3.0 Germany)

Sources used

Microfilm Publication A-3356, German Officer Personnel files, National Archives and Records Adminestration
Wolf Keilig - Die Generale des Heeres (Podzun-Pallas Verlag, 1983)
Andris J. Kursietis - The Wehrmacht at War 1939-1945 (Aspekt, 1999)
French L. MacLean - The Unknown Generals: German Corps Commanders in WW II (Masters Thesis, U.S. Army Command and General Staff Collage, 1988)
Kurt Mehner - Die Deutsche Wehrmacht 1939-1945, Führung und Truppe (Militair-Verlag Klaus D. Patzwall, 1993)
Georg Tessin - Verbände und Truppen der deutschen Wehrmacht 1933-1945
Günter Wegmann & Christian Zweng - Formationsgeschichte u. Stellenbesetzung der deutschen Streitkräfte, 1815-1990, Teile IV, Abt. 1:  Die Dienststellen, Kommandobehörden u. Truppenteile des Heeres, Oct.35-May.45 (Osnabrück, 1998 & 2000)

Reference material on this unit

Hermann Geyer - Das IX.Armeekorps im Ostfeldzug 1941