Apart from the foot soldier the Sturmgeschutz, assault gun was arguably the most cost-effective and versatile weapon of the WW2 German fighting forces. Conceived as an infantry assault weapon, the StuG saw action throughout the war. The introduction of the long gun versions gave it tank killing capability further extending its utility to tank destroyer: the term Sturmgeschutz also later applied to other tank destroyers as the German Army slowly changed from attack to defensive strategies in response to increasing defeats. Howitzer armed StuGs provided heavy weapon support and the capacious flat engine decks furnished infantry transport for accompanying units. As well as the formations in the book’s title, Sturmgeshutz added mobile firepower for many other land based forces including special assault divisions, remote-controlled demolition tank units, infantry, Volksturm, and mountain divisions, and ski troops. As German industry struggled to provide the increasing demand for tanks, assault guns also became substitutes in tank battalions. Photos, almost one to each page, from mostly private collections, show vehicles of the units in which they were deployed and their great variety of field modifications, additions, and camouflage schemes. Using original documents and archives, the author has compiled a comprehensive history of this indispensible AFV and its user formations. Thanks to Osprey for the sample. John Ham MAFVA September 2017.