Prior to joining the SS he was a Hauptmann (Captain) in the Heer (German Army), being awarded the Iron Cross I & II class, the Eastern Front Medal for service on the Eastern Front during the first Russian winter of the war 1941/42, and the German Cross as the commander of a Sturmgeschütz (Assault Gun StuG) Battalion.
As one of the casemate-style turretless Jagdpanzer (tank destroyer, literally "hunting tank") designs, it was developed against the wishes of Heinz Guderian, the inspector general of the Panzertruppen, as a replacement for the Sturmgeschütz III (StuG III).
By 1943 the series of Samokhodnaya ustanovka casemate-armored vehicles had started to appear at the front, starting with the SU-85, and by late 1944 the SU-100, which mounted powerful guns on modern chassis adopting the full-casemate enclosure of the crew compartment as the Germans had done with the StuG III.
On 28 August the Brigade was moved to Estonia and remained in the area of Lake Peipus until early September By 12 September the Brigade's panzer battalion now counted eight Panzer III, one Panzer IV, one Panzer IV, three Panther tanks, one StuG and 17 Sd.Kfz. 251.