When the German army got involved in city fighting in Russia, cities that had been bombed by the Luftwaffe and shelled by artillery actually created tough defense fortifications for Russian troops. These fortifications were becoming costly to overtake as Russian resistance stiffened.

This situation was the basis for the developement of the Strumpanzer IV, also known as "Brummbär" (Grizzly Bear). Designed for close range action, the Strumpanzer IV had 100mm thick frontal armour slopped for added protection. It's 70mm thick sides was formidable as well.

Armed with a powerful 150-mm howitzer, this specialized vehicle offered valuable infantry support. At times battalions up to 45 were deployed.

Ordered in October 1942, 60 were completed by May 1943. These machines served well in the German army however their impact would have been better if the need for such a weapon as this could had been foreseen and in service much earlier.

The first Strumpanzers lacked a machine gun in the hull. Later upgrades provided one as well as more vertical slope to the side armour, periscopes for the driver and a modified gun mounting with a larger collar. A total of 313 Strumpanzers were built throughout World War II. More would have been produced but with the Allies air superiority tacking a toll on German ground forces the versatile Panzerkampfwagan IV chassis was selected to be used for yet another specialized vehicle. So weapon production focused more on the new Flakpanzer IV then the Strumpanzer IV.