On November 18th, 1941, a group of German tank industry representatives visited the Eastern Front, where they inspected captured T-34 tanks. Coincidentally, on the same day the German Weapons Agency initiated the development of a new powerful tank gun. This gun was based on the 75 mm Pak 40, although it had to be shorter in order to fit it into a tank and ensure that its ammunition was small enough to handle within the confined space of a tank's turret.
The gun, named 7.5 cm KwK 40, was installed in the Pz.Kpfw.IV Ausf.F tank. This gave it a key advantage over the Pz.Kpfw.III, which had up until that point been Germany's main medium tank. The Pz.Kpfw.III couldn't fit the new gun, as a result of which it was equipped with the old short 75 mm gun and relegated to a support role, while the Pz.Kpfw.IV took the role of the main medium tank and held it until the end of the war.