This portrait miniature depicts Richard Frewin (1680/81–1761), the physician. An identical miniature also attributed to Richter is in the Bodleian Library, Oxford (Bodleian Library LP 744). The same image was adapted by an unknown artist for a later portrait in oils, c. 1760, at the Royal National Hospital for Rheumatic Diseases, Bath. In the Royal College of Physicians, London, is a copy in stained glass, wrongly identified as Anthony Addington (1713–90), taken from Dr Addington's house in Reading (see Bodleian website).

Miniature painting originally referred to the art of painting in watercolour on vellum (fine animal skin). It developed in the early 16th century out of the tradition of illuminating manuscripts (hand-written books). In England, miniature was predominantly a portrait art. It was practised by specialist miniature painters, such as Nicholas Hilliard (1547-1619). On the Continent, miniature painting as a portrait art was far less of a specialist art. It was often practised by artists who worked in a variety of media, or who also painted portraits in oil in large.

This miniature is by one of the few specialist miniature portrait painters on the Continent, Christian Richter (1678-1732), who was born in Stockholm in Sweden. His brothers were also artists. He first studied medal engraving with Arvid Karlsteen, and possibly also learnt the art of miniature painting from him. He next visited Berlin and Dresden, where he modelled a wax portrait of Augustus II. He was unable to obtain an appointment at the Court of Saxony and went to England instead. He was in London by 1704. There he met fellow Swedes, including the painters Hans Huysing and Michael Dahl. He produced small copies in miniature (watercolour on vellum) of their oil paintings. His skill must have promoted their reputations as well as his own success as a miniaturist in London. It was noted that Richter was 'recommended to Mr Dahl his countryman who encouraged him and promoted him all he could by which means he became really an excellent Master copying from . . . Van Dyke, Lely, Kneller, Dahl and others, and drawing from the life in a very just and good manner'. But at some point Richter succumbed to a disfiguring illness. He was no longer presentable to his clients and he ceased to paint from life. Copying became his only livelihood.