Officially, the Reichswehr of the Weimar era never had more than 100,000 members, no heavy weapons, and no armored vehicles. In the maneuvers, cars with plywood structures served as tank decoys. However, secretly, research and work were already underway; tank prototypes, disguised as "tractors," were driving through the Soviet steppe, and only a few were aware of this. This Spielberger volume presents those developments that later motorized the Wehrmacht in the early phase of World War II. It includes many illustrations, all technical data and facts, and is supported in detail.