In the mid-1960s, inspired by the Swedish Strv S, the Bundeswehr decided to build its own equivalent based on German developments. In 1966, KraussMaffei and Rheinmetall were offered a competition to design a turretless tank with a gun hard-mounted to the hull. Three years later, Rheinmetall presented a prototype, while KraussMaffei withdrew from the competition to focus on producing and upgrading Leopard 1 tanks. However, the new vehicle turned out very expensive to produce, only costing a little less than the Kpz. 70 main battle tank, the program for which was terminated because of high costs. Tests continued until 1972, after which the project was closed.