Before the establishment of the Metropolitan Police in 1829, the maintenance of order and the prevention, detection and punishment of crime in the metropolis was largely the responsibility of the police offices (or public offices) of the metropolitan magistrates. The principal police office was the Chief Metropolitan Magistrate's in Bow Street, which co-ordinated the operations of the other offices with limited help from the Home Office.
The statutory and administrative control exercised by the Home Office over the staffing and operations of the police offices gradually increased (for which see Home Office, Criminal Department).
In 1828 a House of Commons Select Committee on the State of the Police in the Metropolis recommended the creation of an 'Office of Police' under the Home Secretary to control all police establishments in the metropolis outside the City of London itself.
These proposals were incorporated in the Metropolitan Police Act 1829, which gave statutory recognition to the central authority already exercised by the Home Office over the police of the metropolis and provided for the establishment of a Metropolitan Police Office, to control the police establishments of the existing police offices and to direct a new force of Metropolitan Police.
The old police offices retained their separate constables until 1839, but in 1829 the Bow Street foot patrols and in 1836 the horse patrol, which had been established in 1782 and 1805 respectively, were taken over by the new central office. The Thames Police were also incorporated within the Metropolitan Police Force in 1839.
By 1839 the new force had entirely replaced or absorbed the older forces, except that of the City of London. The Metropolitan Police Act 1839 granted the City of London Police statutory recognition, and they remain responsible to the Common Council of the City of London.
The Metropolitan Police Act 1839 converted the police offices into modern police courts with judicial but not executive functions. The Act also extended the Metropolitan Police District from 120 to 700 square miles. Six inner divisions had been set up in September 1829 and by May 1830 these had been extended to 17 divisions. The extension of the Metropolitan Police District in 1839 increased the size of the outer divisions substantially. There are now 24 divisions, including the Thames Division. In 1869 the divisions were grouped into four districts under district superintendents, later called chief constables and then commanders, for the purposes of co-ordination and inspection. The districts were abolished in 1968 but the former district offices remain as offices of the Metropolitan Police Inspectorate.
The Metropolitan Police District was again extended under the London Government Act 1963. Metropolitan police expenditure is borne equally by a police vote and an exchequer grant.
Following an examination by a firm of consultants, the Offices of the Commissioner and the Receiver were merged with effect from 1 April 1968.