BUCKINGHAM PALACE, FROM ST. JAMES'S PARK.
From this point of view is seen the principal façade of Queen Victoria's London residence - that part of Buckingham Palace which faces the east. This side of the huge quadrangle is 360 feet long, and was added in 1846 by Blore, Parliament voting £150,000 for the purpose. The style is German, of the last century, and the architect wisely made no attempt to harmonise the new front with the older parts, built by Nash in the reign of George IV. Formerly there stood here the mansion of the Duke of Buckingham - hence the name; this was bought by George III., and rebuilt by his successor. Before the present front was erected, the Marble Arch served as the gateway to the Palace, which was unoccupied for some years before Her Majesty began to reside here. The rooms on the north side are those used by the Queen.
source: The Queen's London : a Pictorial and Descriptive Record of the Streets, Buildings, Parks and Scenery of the Great Metropolis, 1896