City of London London borough, a status reserved for the other 32 districts (including London's only other city, the City of Westminster). It is also a separate county of England, being an enclave surrounded by Greater London. It is the smallest county in the United Kingdom. The City of London is widely referred to simply as the City (differentiated from the phrase "the city of London" by capitalising "City") and is also colloquially known as the Square Mile, as it is in area. Both of these terms are also often used as metonyms for the United Kingdom's trading and financial services industries, which
Central line (London Underground) it is the only Tube line running east–west through the central core of London, running under Oxford Street and the financial centre of the City of London. Crossrail, due to begin most of its core operation in autumn 2019 with full service by the end of 2019, will provide interchange with the Central line at Stratford, , , and Ealing Broadway, relieving overcrowding in these areas. The Central London Railway (CLR) was given permission in 1891 for a tube line between Shepherd's Bush and a station at Cornhill, and the following year an extension to Liverpool Street was authorised, with