Downing Street is a street in the City of Westminster that houses the official residences and offices of the Prime Minister of the United Kingdom and the Chancellor of the Exchequer. Situated off Whitehall, a few minutes' walk from the Houses of Parliament, Downing Street was built in the 1680s by Irishman Sir George Downing.
For more than three hundred years, it has held the official residences of both the First Lord of the Treasury, the office now synonymous with that of the Prime Minister, and the Second Lord of the Treasury, the office held by the Chancellor of the Exchequer.
The Prime Minister's official residence is 10 Downing Street; the Chancellor's official residence is Number 11. The government's Chief Whip has an official residence at Number 12. In practice, the individuals involved may live in different flats; the current Chief Whip actually lives at Number 9. The houses on the south side of the street were demolished in the 19th century to make way for government offices now occupied by the Foreign and Commonwealth Office.
The term "Downing Street" is used as a metonym for the Government of the United Kingdom.