The sitter was the son of Sir Gerard Napier, 5th Bt. (d.1759), and his wife Bridget, daughter of Edward Phelips of Montacute, and a descendant of the prominent royalist of the same name. He married Elizabeth, daughter of Sir John Oglander, Bt., of Nunwell, Isle of White, but died without issue aged twenty-six, in 1765, when the Baronetcy expired and his estate devolved upon his cousin Humphrey Sturt of Crichel and Horton, M.P. for Dorsetshire.

This picture is one of two portraits of the sitter by Reynolds, to whom both Napier and his wife sat in 1762. A final payment of 120 guineas for both portraits by Lady Napier is recorded in 1769. The original measurements of this picture were recorded as 95 x 57¼in in the 1929 sale catalogue, but it was subsequently cut down, as noted by Waterhouse (op.cit.),the half-length (ie. 50 x 40in.) also sold in the Montacute sale in 1929, lot 45. The misleading entry in the artist's sitters' book under Sir Gerard's name in 1768, three years after his death, is interpreted by Graves and Cronin (op.cit.) as a reminder to finish the portrait. In its reduced form, the composition is almost identical to the other portrait, although Napier is here depicted without a tricorn and the tree in the background is to the left rather than the right.