In February 1943, at the suggestion of the Ministry of Armament, the Krupp company began trials of a new vehicle with the superstructure of the updated StuG III and the new suspension of the Pz.Kpfw. IV H and J. The first vehicles were produced by December 1943. Having canceled the production of the Pz. IV, the Krupp company focused their attention on the production of the new vehicles starting in January 1944. A total of 1,108 vehicles were manufactured, with 31 more converted from existing tanks.