When George III was asked by Lord Eglinton to sit for the most fashionable portrait painter of the day, Joshua Reynolds, he replied: ‘Mr Ramsay is my painter, my Lord.’ Reynolds tried to gain royal notice with two speculative ventures – a portrait of George III as Prince of Wales (OM 1011, 401034) and an oil sketch for a depiction of his marriage to Queen Charlotte (OM 1012, 404353) – both of which remained on his hands. Reynolds was knighted by George III, made first president of the Royal Academy and Principal Painter to the King upon Ramsay’s death in 1784, but never asked to paint anything. That the Royal Collection has a fine group of Reynolds is entirely thanks to George IV, who commissioned portraits at the end of the artist’s life like this one and acquired many examples of his earlier work.

In 1766-8 the Marquess of Rockingham sat to Reynolds for his portrait (English Private Collection); in 1786 he paid Reynolds 150 guineas for this, a replica of that picture, as a present for the Prince of Wales (later George IV). At this date Reynolds's price for a new full-length was 200 guineas; this repetition was thus relatively expensive, for something which required no further sittings or invention. This price suggests that Reynolds and his patron regarded this work, though a repetition, as an autograph Reynolds - as much as anything emerging from his studio could be so called.

The sitter is shown in Garter robes and holding a paper in his right hand, beside a table on which is the plumed hat of the Order; papers and a portfolio lie beneath the table.