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.