One towed artillery gun required a team of six horses and nine men. WW2 German engineers came up with the idea of mounting an artillery gun on top of a tank chassis.

This new technology reduced the amount of resources required to deploy one artillery gun. Artillery self-propelled guns only needed a four or five man crew. They could also be made ready to fire more quickly. This book covers the development and use of this new weapon between 1939 and 1945. One type was successfully used in the invasion of France in May 1940.

More were used on the Eastern Front against Soviet forces from 1941 until the end of the war in 1945. The 'Desert Fox', Ewin Rommel, needed artillery guns that could keep up with his Panzers in North Africa. Horses could not be used in the desert. He was sent 15 cm howitzers mounted on top of Panzer II tank chassis and captured French Army Lorraine 37L tracked armoured supply vehicles.

Rommel's forces in Northern France were equipped with a variety of new artillery self-propelled guns. They were used against the Allies when they invaded the beaches of Normandy on D-Day 6th June 1944.