Adelaide (1792–1849), was the eldest child of George Frederick Charles, Duke of Saxe-Meiningen. She married William, Duke of Clarence (1765–1837), later William IV, in 1818.  William succeeded to the throne on the death of George IV, on 26 June 1830 and was in turn succeeded by his niece Queen Victoria as the couple remained childless. This miniature was probably painted soon after her marriage as the Duchess of Clarence's wedding ring is clearly visible. She is seated at a writing table, wearing a dark blue dress with white lace collar and cuffs and with an ermine robe draped over her chair back.

The artist, Mary Byrne (1776-1845), was the daughter of William Byrne, the engraver. She was a pupil of Louis-Ami Arlaud-Jurine and exhibited at the Royal Academy as Mary Byrne from 1795 to 1805. In 1805 she married the portrait painter James Green, exhibiting thereafter as Mrs James Green. After her husband’s death in 1834, she retired from the profession but continued to exhibit.

The miniature is signed on the lower right My Green.