History of the Metropolitan Police Service been headed by a Commissioner, rather than a Chief Constable which is the highest rank in police forces outside London. The first Commissioners to hold the post were Lieutenant-Colonel Sir Charles Rowan and Sir Richard Mayne. When Sir Charles Rowan died, leaving Sir Richard Mayne as the surviving Commissioner, Captain William Hay was drafted in to jointly run the force with Mayne. However, because the two Commissioners did not agree on methods of running the force, since 1855 it was decided that only one Commissioner would run the force. Metropolitan Police patrols took to the streets on 29 September 1829,
Metropolitan Police Marine Policing Unit Metropolitan Police Marine Policing Unit The Marine Policing Unit (MPU), formally known as Thames Division, is a Central Operations (CO) branch of London's Metropolitan Police Service. Its forerunner, the Marine Police Force, was England's first recognised preventive police unit. The MPU is headquartered on Wapping High Street, in the east of the city, from where it operates a fleet of vessels responsible for policing the River Thames within Greater London. Thames Division was formed in 1839 when the Marine Police Force was absorbed into the Metropolitan Police Force. The original marine force is considered the first preventive police unit in