Self-propelled artillery is an important armored component of every modern army. However, it was not always that way. In fact, at the outbreak of World War II, virtually all artillery was still being moved around by artillery tractors or horses. With one notable exception – the Wehrmacht.
German military doctrine of blitzkrieg required mobile fire support for armored units (tanks and motorized infantry). Which could be provided only by self-propelled guns adequately protected from artillery fire on the battlefield (as they were supposed to provide both indirect and direct fire support).
This requirement gave rise to the development of Sturmgeschütz III (StuG III) – the first mass-produced assault gun (“Sturmgeschütz” means exactly that). And essentially the first mass-produced self-propelled artillery. In fact, StuG III was Germany’s second most-produced armored fighting vehicle during World War II after the Sd.Kfz. 251 armored personnel carrier.
It was also the first operational self-propelled artillery piece that carried their main armament in a fully enclosed and fully-armored casemate – the standard feature of most subsequent designs.
StuG III was built on the chassis of the proven Panzer III tank, replacing the turret with an armored, fixed superstructure mounting a more powerful gun. Initially intended as a mobile assault gun for direct-fire support for infantry, the StuG III was continually modified, and much like the later Jagdpanzer, was employed as a tank destroyer.
Overall, the Sturmgeschütz III series assault guns proved very successful and served on all fronts as assault guns and tank destroyers. Because of their low silhouette, StuG IIIs were easy to camouflage and were difficult targets. Its design proved to be so efficient that Syrian StuG IIIs were in use until the Six-Day War of 1967 (!), and possibly even later.