ThePanzerkampfwagenIV (Pz.Kpfw. IV) Sd Kfz 161, commonly known as the Panzer IV, was amedium tankdeveloped inNazi Germanyin the late 1930s and used extensively during theSecond World War. Its ordnance inventory designation wasSd.Kfz.161. Designed as an infantry-support tank, the Panzer IV was not originally intended to engage enemy armour—that function was performed by the lighterPanzer III. However, with the flaws of pre-war doctrine becoming apparent, and in the face of SovietT-34 tanks, the Panzer IV soon assumed the tank-fighting role of its increasingly obsolete cousin. The most widely manufactured and deployed German tank of the Second World War, the Panzer IV was used as the base for many other fighting vehicles, including theSturmgeschütz IVtank destroyer, theWirbelwindself-propelled anti-aircraft weapon, and theBrummbärself-propelled gun, amongst others.