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 powers and uniform as their regular colleagues. This makes the Metropolitan Police, in terms of officer numbers, the largest police force in the United Kingdom by a significant margin, and one of the biggest in the world. In terms of its police area (primary geographic area of responsibility), leaving its national responsibilities aside, the Met has the 8th smallest police area of the territorial police forces in the United Kingdom. The overall operational leader of the force is the Commissioner, whose formal title is Commissioner of Police of the Metropolis. The Commissioner is answerable, responsible and accountable to The Queen,