166) is a German armoured infantry support gun based on the Panzer IV chassis used in the Second World War.

The Sturmpanzer was a development of the Panzer IV tank designed to provide a vehicle offering direct infantry fire support, especially in urban areas.

It used a Panzer IV chassis with the upper hull and turret replaced by a new casemate-style armoured superstructure housing a new gun, the 15-centimetre (5.9 in) Sturmhaubitze (StuH) 43 L/12 developed by Skoda.

[2] An MG 34 machine gun was carried that could be fastened to the open gunner's hatch, much like the arrangement on the Sturmgeschütz III Ausf.

The fighting compartment was, albeit poorly, ventilated by natural convection, exiting out the rear of the superstructure through two armoured covers.

The Sturmpanzer's baptism in combat at the Battle of Kursk proved that the driver's compartment was too lightly armoured and it was reinforced.

It arrived in Central Russia on 10 June 1943 to prepare for [[battle of Kursk|Unternehmen Zitadelle]] (Operation Citadel), the German attack on the Kursk salient.

The battalion retreated to Nikopol, where it helped defend the German salient there until it was withdrawn back to the Reich at the end of December.

The battalion still had 42 vehicles on hand when the Allies launched their Po Valley offensive in April 1945, but all were blown up to prevent capture, or lost during the retreat, before the war ended in May.

[7] Sturmpanzer-Abteilung 217 was formed on 20 April 1944 at the Grafenwöhr Training Area from cadres provided by Panzer-Kompanie 40 and Panzer-Ersatz Abteilung 18, although it did not have any armoured fighting vehicles until 19 Sturmpanzers were delivered at the end of May.

It had to detrain in Condé sur Noireau, some 170 kilometres (110 mi) behind the front lines, because the Allies had heavily damaged the French rail network.

It remained on the Eastern Front after the Warsaw Uprising was suppressed and was eventually wiped out in East Prussia in April 1945.

Nothing is known of its service in France, but company personnel were sent to Panzer-Ersatz Abteilung 18 at the end of the year and were supposed to have been used in the formation of Sturmpanzer-Abteilung 218.

[9] Sturmpanzer-Abteilung 218 was ordered formed on 6 January 1945 with three companies with a total of 45 Sturmpanzers, but it received Sturmgeschütz III assault guns during February instead.

Only ten Sturmpanzers had been received when the battalion was alerted on 15 October to participate in Unternehmen Panzerfaust, the German coup to forestall Hungary's attempt to surrender to the Allies.

Bomb damage to the rails delayed its arrival until 19 October, by which time it was no longer needed as a pro-German government had been installed.