City of Westminster is an inner London city and borough. It has been the capital city, "de facto", of multiple British governments. Historically in Middlesex, it is immediately to the west of the older City of London. The city and borough's southern boundary is the Thames. It occupies a large area of central Greater London, including most of the West End. To its west is the Royal Borough of Kensington and Chelsea, and to its north is Holborn in the London Borough of Camden.