The 3.7 inch Howitzer (officially known as Ordnance, Q.F. 3.7-inch How Mk 3 on Carriage Mk 2P) was originally designed before World War One, to replace the earlier 2.75 inch (70mm) Howitzer in use at the time. However, it only entered service until in 1917 and was used in Palestine and East Africa by British and Indian Mountain batteries. Between the wars they were used on the NW Frontier of India and developed a reputation for good accuracy.
 It was originally designed for use as pack artillery, with the barrel being of a two-piece 'screw-jack' assembly held together by a junction nut in the middle. This meant it could be disassembled and carried by mules (in 8 loads) or towed by short draught (no limber), but in line with the general mechanisation of the British Army, in the 1930s, it was adapted for vehicle towing, using the Mk 2P carriage.