Designed and developed to make it possible for the RAF to mount attacks on German targets from bases in the UK, the Handley Page V/1500 must be regarded as the first practical strategic bomber. Larger in size than the O/100s and 0/400s that had preceded it, the V/1500 was powered by four Rolls-Royce engines mounted in tandem pairs between the wings, outboard of the fuselage, but was in other respects similar in overall configuration to the earlier bombers. The initial contract was placed with Harland and Wolff of Belfast, but orders eventually totalled more than 200, of which the majority were cancelled at the end of World War 1. The prototype, assembled by Handley Page from components manufactured by Harland and Wolff, was flown for the first time during May 1918. This differed primarily from production aircraft by having a single large cooling radiator to serve all four engines, the standard installation becoming one hexagonal radiator forward of each pair of engines. This larger aircraft provided accommodation for a crew of five to seven.
When the armistice was signed only three V/1500s were ready for operational use, these standing by with No. 166 Squadron at Bircham Newton, Norfolk where they had been frustrated by bad weather from attacking targets in Germany. The type saw only limited post-war service with the RAF, gradually being replaced by the Vickers Vimy. One was used to record the first through flight from England to India: taking off on 13th December 1918, the aircraft flew via Rome, Malta, Cairo, and Baghdad to Karachi, which it reached on 30th December. This aircraft was used in May 1919 to make a bomb attack on Kabul during the problems in Afghanistan. Another V/1500 was shipped to Newfoundland with the object of making a first west-east flight over the North Atlantic, but this project was abandoned when Alcock and Brown achieved the first crossing in a Vickers Vimy. The post-1924 designation was H.P.15.