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 Service which patrolled a number of Greater London's major parks, was merged with the Metropolitan Police in 2004, and those parks are now policed by the Royal Parks Operational Command Unit. There is also a small park police force, the Kew Constabulary, responsible for the Royal Botanic Gardens, whose officers have full police powers within the park. A few London borough councils maintain their own borough park constabularies, though their remit only extends to park by-laws, and although they are sworn as constables under laws applicable to parks, their powers are not equal to those of constables appointed under the Police