It was formed in the Wehrkreis XII recruitment and training district in Wiesbaden in October 1936 and was mobilized before the outbreak of war at the end of August 1939.

At the start of World War II the corps were part of the 1st Army and based in the Saar region.

In Operation Barbarossa in June 1941 the corps were attached to Panzer Group 2 for the attack on the stronghold of Brest-Litovsk.

Following Operation Bagration, the huge Soviet counter-attack in 1944, XII Corps were forced to retreat in bad condition and in July 1944 were finally destroyed in a pocket east of Minsk.

The corps was reformed in April 1945 to defend the middle Rhine and Thuringia under General Herbert Osterkamp.