Buckingham Palace
Buckingham House was built for the Duke of Buckingham in 1703. George III purchased the house in 1762 and used it as one of the royal family's London homes. George IV employed John Nash to build a new palace round the old house. Nash designed the building with Marble Arch as the main entrance. Marble Arch was later moved to Hyde Park. It was not until 1837 that Queen Victoria made Buckingham Palace the royal family's principal London residence.
Primary Sources
(1) William Pyne, The Microcosm of London (1808)
The additions which have been made to this palace, have been so contrived as to render it a convenient residence for their majesties and princesses; as well as to form a suite of rooms for the royal collection of books, drawings, maps, plans, etc. Thirteen apartments are occupied by the King, twelve by the Queen and ten by the Princesses.