Despatch rider

A despatch rider (or dispatch) is a military messenger, mounted on horse or motorcycle (and occasionally in Egypt during World War I, on camels).^[1]

In the UK 'despatch rider' is also a 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.