[1] The Constabulary can trace its history back to 1686 when the Royal Navy needed an organisation to prevent dockyard crime.

So the Secretary to the Admiralty - Samuel Pepys, the diarist - formed a force of 'porters, rounders, warders and watchmen' to guard the Naval Yards.

Porters identified and escorted visitors, rounders patrolled the yard, warders were responsible for the keys and backed up the porters at the gates, and the part-time watchmen guarded buildings and areas by night.

Rewards for obtaining convictions quickly led to corruption, so the force was 'cleaned up' and then abolished.

In 1860 dockyard divisions of the Metropolitan Police took over and senior Naval officers became magistrates.