[[Video:Number 10 goes boom.jpg|right|thumb|Number 10 is destroyed. (TV: World War Three)]] 10 Downing Street was the residence of the Prime Minister of the United Kingdom and seat of the government of Great Britain, and later the UK from the 17th century to the early 21st century.
Lord Salisbury was the Prime Minister in July 1900. He was the last person who held that office to refuse to use 10 Downing Street as his official home. He instead allowed his nephew Arthur Balfour to use it. Balfour later became Prime Minister himself. (AUDIO: Upstairs)
As the Ninth Doctor recalled, a Mr Chicken owned the property and lived there. By 1991, the Cabinet Room was almost impregnable for the safety of government officials when three inches of steel was installed into every wall of the room. During the Slitheen takeover of 2006, it was destroyed by a harpoon missile. (TV: World War Three) The explosion levelled the building and killed all but one of the Slitheen. (TV: World War Three, Boom Town)
By the time that Harold Saxon took office in 2008, it had been re-built. Saxon, who was in reality the Master, considered the Cabinet to have betrayed him [disputed statement] and so gassed them to death in the Cabinet Room. (TV: The Sound of Drums)