Wars were directed from within it, as were the key decisions about the end of the empire, the building of the British nuclear bomb, the handling of economic crises from the Great Depression in 1929 to the great recession, and the building up of the welfare state.

Some of the most famous political figures of modern history have lived and worked in Number 10, including Robert Walpole, Pitt the Younger, Benjamin Disraeli, William Gladstone, David Lloyd George, Winston Churchill and Margaret Thatcher.

Number 10 has 3 overlapping functions. It is the official residence of the British Prime Minister: it is their office, and it is also the place where the Prime Minister entertains guests from Her Majesty The Queen to presidents of the United States and other world leaders. The Prime Minister hosts countless receptions and events for a whole range of British and overseas guests, with charitable receptions high up the list.

The building is much larger than it appears from its frontage. The hall with the chequered floor immediately behind the front door lets on to a warren of rooms and staircases. The house in Downing Street was joined to a more spacious and elegant building behind it in the early 18th century. Number 10 has also spread itself out to the left of the front door, and has taken over much of 12 Downing Street, which is accessed by a corridor that runs through 11 Downing Street – the official residence of the Chancellor of the Exchequer.