The StuG III served as an assault gun in the German Army during World War 2. The platform stemmed from a German Army need to supply ground troops with a mobile artillery system where traditional armored elements such as tanks were not made available. The German requirement was for a system to have to mount a formidable main gun upon a capable hull that could provide a mechanized element to advancing fronts in keeping with blitzkrieg concepts. The resulting system - though at the time seen as more of an interim solution - became the Sturmgeshutz (StuG) III which utilized the existing Panzer III medium tank hull and fitted a 75mm main gun in a fixed position within the superstructure.
The StuG III entered production in January of 1940. The system mounted a powerful 75mm (7.5cm) StuK 40 L/48 main gun into what was essentially a turretless, all-hull assault gun / tank destroyer design. While some may wonder why the 75mm gun was not simply installed into existing Panzer III tanks, the reality was that the selected 75mm gun was simply too long to fit into Panzer III turrets, these being originally designed to house the smaller 37mm main gun series (though progressively upgraded to 50mm and 75mm in later models). However, this combination of existing gun/hull materials cut down on production costs and time. The major drawback of such a design was of course the lack of a traversing turret - this forcing the crew to maneuver the entire tank in the direction of the enemy. Later models would add a self-defense 7.92mm machine guns for crew protection. Crew accommodations amounted to four personnel. Externally, the design of the StuG III was characterized by the small six road wheels and, in some models from 1943 onwards, side skirt armor for additional point protection.
The StuG III appeared in a few variants with earlier ones mounting the StuK 37 L-24 main gun. The definitive StuG III came in the form of the Ausf F model which sported an StuK 40 L/43 main gun. This models designation changed slightly to showcase the difference from previous ones and became the SdKfz 142/1 and would sometimes be known as the StuG 40 from that point on. Additionally frontal armor protection was further addressed and continued to be so in future variants.
Production of the StuG series numbered in the thousands with a majority of production facilities concentrating on StuG IIIs by war's end. The system proved so effective and vital that even captured Soviet versions turned up with the Red Army sporting a variety of Soviet main armaments. Finland was also the other major user of the StuG III. Easy to build and relatively inexpensive when compared to other German systems, the StuG III series became a pivotal battlefield component of the German Army up through the closing months of the world conflict.