The Bishop was a first British self-propelled artillery vehicle based on the Valentine II chassis. The official name was Ordance QF 25-pdr Mk2 or 3 on Carrier Valentine 25-pdr Gun Mk1. Throughout 1941 the British and Commonwealth Divisions in the Western Desert had little to combat the well armoured German Medium Tanks apart from the almost useless Boys Anti-Tank Rifle and the issue 2-pdr (40mm) Anti-Tank gun of the Divisional Anti-Tank Regiments. Whilst these were reasonably effective against lightly armoured Italian Tanks, they were completely inadequate to take on the more heavily armoured German Tanks. So a rushed conversion was made to create a self-propelled gun armed with the 25 Pounder gun- howitzer.
As a result, the vehicle had numerous problems.
The Bishop's gun had a limited elevation which lowered its range considerably. In order to compensate, its crews would often have to build large ramps out of the earth so that the vehicle could be tilted. Also, in order to accommodate the 25 pounder gun, the vehicle also had to have a high silhouette.
Due to these factors, compounding the Valentine's characteristic slow speed and thin armor, the Bishop was poorly received almost universally and soon replaced by the M7 Priest and Sexton. Only around 140 of these vehicles were produced.
It first saw action during the Second Battle of El Alamein in North Africa and continued to serve during the early part of the Italian Campaign.