The Metropolitan Police District (MPD) is the police area which is policed by the Metropolitan Police Service in London. It currently consists of Greater London, excluding the City of London. The Metropolitan Police District was created by the Metropolitan Police Act 1829 as an ad hoc area of administration because the built up area of London spread at the time into many parishes and counties without an established boundary. The district expanded as the built up area grew and stretched some distance into rural land. When county police were set up in England the forces of Essex, Hertfordshire, Kent and Surrey did not include those parts of the counties within the MPD and Middlesex did not have a county force. Similarly, boroughs in the MPD that elsewhere would have been entitled to their own police force did not have them.