The rapid manoeuvre warfare practiced in the North African Campaign led to a requirement for a self-propelled artillery vehicle armed with the 25-pounder gun-howitzer. In June 1941, the development was entrusted to the Birmingham Railway Carriage
and Wagon Company. A prototype was ready for trials by August and 100 were ordered by November 1941. The result was a vehicle with the formal title: "Ordnance QF 25-pdr on Carrier Valentine 25-pdr Mk 1"