Numbers 9, 10 and 11 St James's Square were built on the site of Chandos Place, a house of 1675 or 1676 that was redeveloped in 1735-6. Sir William Heathcote of Hursley, Hampshire owned the centre house, that is, No. 10 (now Chatham House), which was built by speculative builder Benjamin Timbrell with Henry Flitcroft as the architect; it remained in the Heathcote family until 1890. From 1814 to 1819, the house was occupied by T. F. Heathcote (1769-1825, succeeded to the baronetcy in 1819) for whom Dance prepared a decorative scheme for Flitcroft's first floor Octagon and designed a fitted bookcase.

In 1925, Sir Herbert Baker's alterations and additions for the house's new owner, the Royal Institute of International Affairs, destroyed the Octagon and though, according to the Survey of London, the dome with its lantern existed as a room on the second floor, its traces of octagonal coffering were not what is shown on Dance's design catalogued here, and thus it is uncertain whether his proposals were carried out. Today there is a squareish open-plan office with a partly glazed ceiling located on the second floor above the site of the Octagon.

The Heathcote family seat, Hursley in Hampshire, was three miles from that of Dance's brother Sir Nathaniel Dance-Holland (Farington, 2 November 1807), and perhaps the commission came through that source.

LITERATURE. Survey of London, XXIX, Parish of St James, Westminster, Part I, 1960, pp.122-32.