St James's Square was developed by Henry Jermyn, Earl of St Albans following the Restoration in 1660. St Albans leased plots for speculative builders to erect individual houses. It was a convenient location for aristocrats with duties at St James's Palace, and soon became the most fashionable address in town. Most of the houses were rebuilt during the eighteenth century, but it became less fashionable during the nineteenth century when the square was populated by wealthy tradesmen and clubs rather than aristocrats. None of the houses in the square remain residential, and are mainly used as offices.

Little is known of the original seventeenth-century house at number 33 St James's Square. In 1770-72 the house it was replaced to designs by Robert Adam with a three-storey, four-bay house, facing the square, and with a seven-bay north side on Charles II Street. This has since been much extended. Adam's work was carried out for the Hon. George Hobart.

The Hon. George Hobart (1731-1804), was the fourth son of the 1st Earl of Buckinghamshire (d 1756). He served as MP for St Ives in 1754-61, and Bere Alston in 1761-80; lived in St Petersburg in 1762-63 as secretary to his brother, John 2nd Earl of Buckinghamshire’s Embassy to Catherine the Great; and in 1757 he married Albinia, the daughter and co-heir of Lord Vere Bertie, the third son of Robert, 1st Duke of Ancaster. He was also a great lover of the opera, and promoted the Haymarket Opera House.

An inscription on one of the drawings for the fabric of the house suggests that 33 St James’s Square was rebuilt for Hobart at the behest of his brother, the 2nd Earl. This is unknown, but most of Adam's designs were executed, and his three ceilings on the first floor survive in situ.

Substantial alterations and extensions were made to the house by the 2nd Lord Eliot (later 1st Earl of St Germans) to designs by Sir John Soane (1753-1837) in 1805-23. In 1855-69 the house belonged to the 14th Earl of Derby, Prime Minister in 1852, 1858-59 and 1866-68, and a fourth storey was added in the 1870s for his son, the 15th Earl of Derby. Derby sold the building to the English and Scottish Law Assurance Association in 1910 for £54,000, and they undertook further works in 1911, including a stone balcony, stone facing to the ground storey, a mansard roof, and various alterations to the interior, all to designs by Messrs Edmerton and Gabriel. The house was remodelled in 1999. At this time some of the Soane interiors were demolished in favour of reproduction Adam interiors. The building is now used as offices.

Literature:
A.T. Bolton, The architecture of Robert and James Adam, 1922, Volume II, Index pp. 49, 75; F.H.W. Sheppard (ed.)., Survey of London, Volumes XXIX and XXX, 1960, pp. 206-10, and pls. 186-89; B. Weinreb, and C. Hibbert, The London encyclopaedia, 1983, pp. 740-42; D. King, The complete works of Robert & James Adam and unbuilt Adam, 2001, Volume I, pp. 264, 271-72; S. Bradley, and N. Pevsner, The buildings of England: London 6: Westminster, 2003, pp. 624-25, 633; P. Dean, Sir John Soane and London, 2006, p. 227; History of Parliament online: 'Hobart, Hon. George (1731-180), of Nocton and Blyborough, Lincs.'; British listed buildings online: 'City of Westminster, St James’s Square, No. 33'

Frances Sands, 2013