After the Great War the British Government had a huge debt problem.  They asked Sir Eric Campbell Geddes (1875-1937), a prominent Conservative businessman, to look at the problem and recommend solutions.  He formed the Committee on National Expenditure and one of their decisions was to cut the defence budget by 42%.  They recommended that the Metropolitan Police be withdrawn from Dockyards and replaced by a new, cheaper alternative.  The Royal Marine Police was created by an Order in Council dated Friday October 13th 1922, as a result of which the Royal Marine Artillery and Royal Marine Light Infantry were amalgamated on June 22nd 1923 and the Royal Marine Police formed from their members.

Long-service pensioners and non-commissioned officers were recruited to the Police Force.

Progress was slow, however.  First the powder hulks above Saltash were handed over to the Royal Marine Police Force.  They were followed by the Royal Naval Ordnance Depot at Bull Point and then the Gun Wharf.  From Wednesday May 4th 1927 they took over the guarding of the Royal William Victualling Yard and the Royal Naval Armament Depot within it at East Stonehouse.

Thus after over sixty years the Royal Marine Police Force took over the guardianship of the North Yard on Monday April 23rd 1934 and the South Yard as from midnight on Sunday August 12th 1934.  Captain T H Burton, Royal Marines (retired), was the officer in charge.  Devonport was the last Royal Dockyard to make the changeover from the Metropolitan Police Force.

The Royal Marine Police Special Reserve was founded in 1939.

As from Sunday October 2nd 1949 the Admiralty Civil Police Force, Royal Marine Police Force and the Royal Marine Police Special Reserve became the Admiralty Constabulary.