A despatch rider (or dispatch) is a military messenger, mounted on horse or motorcycle (and occasionally in Egypt during World War I, on camels).
In the UK 'despatch rider' is also the most common term used for a motorcycle courier.
Despatch riders were used by armed forces to deliver urgent orders and messages between headquarters and military units. They had a vital role at a time when telecommunications were limited and insecure. They were also used to deliver carrier pigeons.
In the British Army, motorcycle despatch riders were first used in the World War I by the Royal Engineers Signal Service. When the War Department called for motorcyclists to volunteer with their machines for despatch work at the start of August 1914, the response was huge. The London office had 2000 more applicants than places, and a similar response was reported in regional centres around the country. If a rider and machine were approved then £10 was paid immediately, £5 to be paid on discharge (unless due to misconduct), and pay was 35s per week. The motor cycle would be taken over at valuation price, or will be replaced with a new one at the close of operations. Enlistment was for one year or as long as the war might last. The preference was for 500cc single cylinder machines and the horizontally-opposed twin cylinder. All machines had to have a "change speed gear". The following list of spares was also required to be carried :
Recruitment was not just for the army; the Admiralty in Chatham bought 50 Triumphs in 1914 for despatch rider duties, and many unsuccessful applicants were accepted by Scotland Yard on different terms to patrol country districts and distribute royal proclamations. These bikes carried a plate on the front with the lettering "O.H.M.S.".
As the war progressed the wide variety of volunteered machinery presented maintenance and spares problems, and so were progressively replaced by a limited range of military models, and in specific regions of the world or parts of the service only one of these models might be found, for example the RAF (formerly the RFC) exclusively used P&M motorcycles by the later stages of the war (they also included female riders).