The British demand for portraiture increased rapidly in the eighteenth century as members of the wealthy middle class became art patrons in their own right. Arthur Devis was a provincial artist who came to live in London, where sophisticated portraitists of the upper class such as Reynolds and Gainsborough dominated the art world. Devis received commissions from the middle-class landowning families, merchants, and officials who lived in smaller cities outside London.
This informal portrait is a conversation piece, a genre favored by Devis. The figures, while full-length, are relatively small and are placed somewhat back in the landscape; the background is larger and more detailed than in traditional portraiture and describes the subjects' personal and social context.
Devis devised a repertoire of postures and gestures that he used to express the social status of his sitter. Arthur Holdsworth, governor of Dartmouth Castle, is shown seated, an alert, attentive expression on his face. The ship sailing into the mouth of the River Dart in the background may be a reference to the Holdsworth family's trading business. Holdsworth's brother-in-law, Thomas Taylor, stands behind him in riding clothes. The third man is Captain Stancombe.
More information on this painting can be found in the Gallery publication British Paintings of the Sixteenth through Nineteenth Centuries, which is available as a free PDF https://www.nga.gov/content/dam/ngaweb/research/publications/pdfs/british-paintings-16th-19th-centuries.pdf