The chimneypiece was executed in accordance with these drawings, and survives in situ. It is based on the Confessor’s tomb, and the Cosmati pavement at Westminster Abbey.

Harris has described the chimneypiece as ‘an attempt to produce Italian thirteenth-century cosmati work (glass and stone mosaic) in a 1760s English drawing room, it is a freak, an antiquarian curiosity dreamed up and directed by Horace Walpole’.

According to Stillman, Adam’s neo-classicism is more apparent in the chimneypiece than in his ceiling for the round drawing room, as various features are taken from his characteristic repertoire, classicising much of what he borrowed from the Confessor’s tomb.

One of the working drawings (Adam volume 18/61) is in very poor condition, suggesting that it has been used by the craftsmen who produced the chimneypiece.