Number 10 was a cheap speculative build by a former spy
Britain's most famous front door belongs to a house Winston Churchill called shaky and lightly built. Its namesake, Sir George Downing, was a spy for Oliver Cromwell and later Charles II who turned property developer, throwing up quick, cheap town houses on soft ground. He never lived in one himself.
Downing bought a lease beside St James's Park in 1654, planning a row of houses for persons of good quality. A family holding an older lease refused to leave, and he had to wait 30 years. Finally, between 1682 and 1684, he built a cul-de-sac of two-storey houses designed by Christopher Wren, on shallow foundations. He died in Cambridge a few months after they were finished, and his fortune later founded Downing College there. The house now famous as Number 10 was numbered 5 until 1787.
It was really three buildings stitched together. Behind the town house stood a grand mansion dating from around 1530, known simply as the House at the Back, once home to Thomas Knyvet, who captured Guy Fawkes in 1605. When it reverted to the Crown, George II offered it to Robert Walpole in 1732. Walpole took it on one condition: the gift would go to his post as First Lord of the Treasury, not to him as a private man, and every prime minister since 1905 has held that post.
Walpole persuaded a neighbour, one Mr Chicken, to vacate his cottage, and hired William Kent to merge the mansion, the cottage and the town house into one. The work took three years, and a cost first estimated at 8,000 pounds probably passed 20,000. The family moved in during September 1735.
Few early prime ministers bothered living there. Expensive to maintain and often run-down, the house was slated for demolition several times, yet it survived, and in 1985 Margaret Thatcher ranked it among the nation's most treasured heritage jewels. Today it is a Grade I listed building of roughly 100 rooms, with the prime minister's private flat on the third floor, offices and state rooms below, and a half-acre garden behind.
Source: 10 Downing Street
