Geddes was born in Edinburgh on 5 April 1783. Although he travelled to London to study at the Royal Academy Schools in 1806, by 1810 he had returned to Edinburgh and established himself as a portrait painter, encouraged by his close friend, Sir David Wilkie (1785-1841). Geddes painted and etched old masters (of which he himself had a considerable collection) and travelled to Italy, France and Holland. In 1827, he married Adela, daughter of Nathaniel Plimer.
Very few portraits of Nathaniel Plimer are known, only an etching by Geddes (British Musuem, London) and a portrait miniature (private collection), and on the basis of physical and physiognomical comparison with these, the identification of the current portrait would appear plausible. Plimer is previously thought to have remained in London throughout his career, however Smailes has now discovered that he was recorded in the Edinburgh street directories between 1804-1813/14 and exhibited with the Associated Society of Artists in 1808 (H. Smailes, Andrew Geddes 1783-1844, Edinburgh, 2001, pp.23-24). Plimer met Geddes during this period and painted him and his daughter.