Marlborough House is a Grade I listed mansion in the City of Westminster, central London, in The Mall, London, east of St James's Palace. It was built for Sarah Churchill, Duchess of Marlborough, the favourite and confidante of Queen Anne. The Duchess wanted her new house to be "strong, plain and convenient and good". The architect Christopher Wren and his son of the same name designed a brick building with rusticated stone quoins (cornerstones) that was completed in 1711. For over a century it served as the London residence of the Dukes of Marlborough.
The house was taken up by the Crown in 1817. In the 1820s plans were drawn up to demolish Marlborough House and replace it with a terrace of similar dimensions to the two in neighbouring Carlton House Terrace, and this idea even featured on some contemporary maps, including Christopher and John Greenwood's large-scale London map of 1830, but the proposal was not implemented. Marlborough House was primarily used by members of the Royal Family, especially dowager queens and eldest sons of the sovereign. Queen Adelaide was given the use of Marlborough House from 1831 until her death in 1849.
From 1853 to 1861 Prince Albert, the consort of Queen Victoria, arranged for the building to be used by the "National Art Training School", later the Royal College of Art. It was then (1861–1863) substantially enlarged to designs by Sir James Pennethorne, who added a range of rooms on the north side and a deep porch. This was done for the Prince of Wales, later King Edward VII, and his wife the Princess of Wales, Alexandra of Denmark, who made their home the social centre of London, and lived there until his mother died in 1901, when Edward acceded the throne and they moved to nearby Buckingham Palace.