Alexandre-Jean-Baptiste Piochard D'Arblay (1748-1818)
"From the original crayon drawing in the possession of F. Leverton Harris" (Hill xii)
Source: Hill, facing p. 54
The National Portrait Gallery's photogravure by Emery Walker (dated 1905, plate size 5 1/2 in. x 4 1/8 in.) is also "after an unknown artist," and very similar.
D'Arblay was one of the French émigrés who sought refuge in Surrey after the French Revolution, and met his future wife, Frances Burney, there.
Image scan, text and formatting by Jacqueline Banerjee. [Click on image to enlarge.]
You may use the image without prior permission for any scholarly or educational purpose as long as you (1) credit the source and (2) link your document to this URL or cite it in a text document.