John Gawler was a Solicitor of the Inner Temple who resided at Ramridge House, Hampshire. He married Caroline Bellenden, eldest daughter of John, 3rd Lord Bellenden, on 18 March 1760. Gawler sat to Reynolds in 1776 and 1777. The prototype for Bone's work was a portrait of Gawler by Sir Joshua Reynolds, c.1777, originally with a companion portrait of Caroline, in the collection of the Duchess of Roxburghe at Floors Castle.
Bone's preparatory sketch from 1820 bears the inscription 'after the original by Sr J. Reynolds for Mr Ker April 1820', and is held in the archive collection of the National Portrait Gallery, London, inv. no. D17358. Bone also made sketches from Reynolds's double portrait of Henry Gawler and John Bellenden Gawler (later Ker) in the same year (NPG inv. no. D17359); Bone's copy in enamel of this portrait was sold Christie's, London, 7 December 2004, lot 121. For more information see R. Walker, op. cit. p. 326, nos. 213-214. The National Portrait Gallery also holds a mezzotint version of John Gawler's portrait, dated 1777, by John Raphael Smith (1752-1812) after Sir Joshua Reynolds (inv. no. D2424).