Spencer House, London

Spencer House at 27 St James's Place is a mansion in St James's, London, England, and is held from the owner (Earl Spencer) by Lord Rothschild on a long lease.
The house was commissioned by John, 1st Earl Spencer, in 1756, the Earl requiring a large townhouse to cement his position and status. The architect he chose was John Vardy who had studied under William Kent. Vardy is responsible for the facades of the mansion that we see today. The house is Grade I listed on the National Heritage List for England.
Design.
In 1758, James "Athenian" Stuart, who had studied the arcadian values of Ancient Greek architecture, replaced Vardy as the architect of the project; as a direct result of this Spencer House was to have authentic Greek details in the internal decoration, and thus it became one of the first examples in London of the neoclassical style, which was to sweep the country.
As the home of successive Earls and Countesses Spencer, the staterooms of the house became a theatre for the pageant that was London high society. The Spencer family lived at the mansion continuously until 1895, when the house was let. The Spencers returned for a brief while in the first quarter of the 20th century; then again the house was let, at various times as either a club or offices. During the Blitz of the Second World War, it was stripped of its few remaining authentic treasures, specially made furniture, and fireplaces.
Present day.
Spencer House remains in the ownership of The Earl Spencer, the current titleholder being Charles Spencer, 9th Earl Spencer, brother of Diana, Princess of Wales. However, since the Second World War, the house has been continuously let out. In 1948 it was leased to Christie's auctioneers; in 1956 to the British Oxygen Company, and in 1963 to the Economist Intelligence Unit. In 1986, RIT Capital Partners, the family company of Jacob Rothschild, 4th Baron Rothschild, secured a 96-year lease (with an additional 24-year option), and in a highly acclaimed restoration, returned the state rooms and garden to their original appearance. The lease of Spencer House is valued at £35 million in the 2017 RIT Capital Partners Plc annual report.
Together with Lancaster House, Bridgewater House, Dudley House and Apsley House, Spencer House is one of the last of the many aristocratic townhouses which once adorned central London.