The Sturmgeschuetz (storm or assault gun) was developed in the 1936-39 period to provide armoured support for the infantry. This came about largely because the new tanks being produced were destined for the panzer (armoured) divisions. In a battlefield situation there was no guarantee that tanks from an armoured division would be available to support the infantry. Thus the idea of the assault gun regiment organic to an infantry division came about. The new assault gun developed was based on the Panzerkampfwagen III Designated Strumgeschuetze III, the assault gun had a low superstructure with its main armament mounted in the superstructure front and given limited travers. Pre-production vehicles were battle-tested in the invasion of France in May 1940, and then ordered into large scale production.