Radnor House, Twickenham, was built in 1673 and from 1722 it was owned by John Robartes (1686-1756/7), who succeeded as 4th Earl of Radnor in 1741. This mirror painting must show the house largely created by him, although there are too many differences from the Boydell print of 1753 to be explained by the Chinese artist's licence. The mirror-painting shows an additional bay projection and a low tower on the left of the house itself. In the foreground, the Chambers-style Chinese pavilion on the left waterfront has had an additional storey added and a magnificent pagoda roof in place of the earlier pitched roof.
These additions may have taken place between 1753, the date of the Boydell print, and 1756 or 1757 when Lord Radnor died. The picture from which the print was made might date from earlier in the 1750s than 1754. The alternative is that the alterations were undertaken by Lord Radnor's heir, his steward John Atherton Hindley, who is not usually credited with having improved the house. Walpole's remarks about him are mostly about his impending insolvency, which led to the house being sold in 1779.
Horace Walpole was no friend of Radnor but both he and Gray admitted the beauty of the house's position, of which Gray wrote 'nothing can spoil so glorious a situation, which surpasses everything round it' (Toynbee and Whibley, eds., Correspondence of Thomas Gray, vol. I, p. 405). The house was extravagantly decorated inside for Radnor, inclduing several painted ceilings by Jean-François Clermont (1717-1807) and was remodelled externally in 1846-7 in the Italianate style. In 1902 the property was bought by Twickenham Council, for its park. In the late 1930s the council proposed to demolish the house to enlarge that park, but a campaign led by Queen Mary and the newly founded Georgian Group led to its reprieve, only for it to to be destroyed by a bomb in 1940.