On 24 May 1809, around 2,500 French prisoners of war arrived at Dartmoor Prison.

The prison had been built during the Napoleonic Wars, when Britain needed secure places to hold men captured in the long war with France. Dartmoor did not begin as the civilian prison it later became. Its first purpose was military: large-scale confinement.

The place was part of the plan. Princetown stood high on the moor, away from major towns and ports. That made escape harder and kept prisoners at a distance from ordinary civilian life. The moor did not need drama added to it. Its usefulness was plain enough: space, isolation and a harsh setting for a prison built to hold thousands.

The arrival of the French prisoners turned Dartmoor from a new building into a working institution. Behind the fighting at sea and on the continent sat another part of war: transport, guards, food, buildings and the long business of keeping captured men alive and contained.

Dartmoor later became better known as a prison for convicts. That later reputation can obscure its beginning. On 24 May 1809, its story was still tied to the European war. One of Britain’s best-known prisons began as a holding place for French prisoners on an exposed Devon moor.