The sitter has been identified as Richard Milles of Nackington, (about 1735 - 1820), Member of Parliament for nearby Canterbury from 1761-80. Milles probably sat for this portrait when he was in Rome during his Grand Tour. He points to a map inscribed with the place name 'Grisoni', a Swiss Canton which he probably visited on his way to Italy. The classical bust of the Emperor Marcus Aurelius alludes to the sitter's interest in classical antiquity. Batoni painted a half-length portrait of Milles and a miniature on ivory (the latter in the Fitzwilliam Museum, Cambridge).
The mood of the portrait is one of assurance and ease, created by the artist to dignify the sitter.
