The Entwicklungsfahrzeug series program was conceived by Oberbaurat Kniepkamp in May 1942 and authorized as a project in April 1943. The E 10 contracts for the smallest Panzer in the series. The E 10 was primarily developed as a Panzer chassis to test new components, especially engines, transmissions, and suspensions. Many parts were to be shared by the E 10 and the E 25. A Magirus drawing shows the E 10 outfitted with the 7.5 cm Pak 39 L/48. The type of weapon for series production was still unsettled in January 1945 but was to be based on the most modern weapon available. According to Kniepkamp in postwar interrogations, the drawing for the E 10 were completed in the Summer of 1944 and contracts given to Magirus to complete three trial vehicles. The three hulls were being made in Silesia, but were not finished when the Russians arrived.
