The Panzer (PzKpfw) III was originally meant to be a reconnaissance tank but during the early war years it served as the mainstay of the Panzer divisions. The first four marks, Ausf A-D, were experimental and the first production model was the Ausf E. Only 98 PzKpfw Ill's were available for the invasion of Poland in 1939, but this number was rapidly increased with, ultimately, a total of 6,157 PzKpfw Ills being constructed. This title describes in detail the gun tank versions, from the very first lightly armed models that were progressively developed and improved up to those with a 50mm or 70mm gun.