Oval miniature in watercolour in an oval gilt metal suspension locket. The sitter is shown head and part shoulders, facing forward against a brownish background, but with his head turned slightly to his right. He has brown eyes, wears a lace cravat over a blue silk cloak or sash running across the body over his right shoulder, and a full-bottomed brown wig. To the left the image bears the 'PC' monogram of Peter Cross (c.1645 -1724) who was long mistakenly known as Lawrence Crosse, mainly owing to misreading as 'LC' of this common signature of his (which he modelled on Sir Peter Lely's).

Cross was a London miniaturist who in 1678 became ‘Lymner in Ordinary’ to Charles II. His family lived in Henrietta Street, Covent Garden, as did the more famous Samuel Cooper, and it has been suggested that Cross trained under him. This miniature is inscribed twice on the reverse: 'Dalkeith' in pencil and ‘The Earl of Dalkeith’, in scratched form, and the sitter is James Scott, eldest surviving son of James Scott, Duke of Monmouth (1649 -85).

Monmouth was the eldest illegitimate son of King Charles II , by Lucy Walter, and was originally given the surname Crofts after William, Lord Crofts, a gentleman of Charles's bedchamber, in whose care he was placed as a child. He formally changed his name to Scott as a condition of his arranged marriage in 1663 to the wealthy Scottish heiress Anna Scott, who was already Countess of Buccleuch in her own right albeit only 12 (and he only 14) at that time. This followed his public acknowledgement by his royal father, and his creation as Duke of Monmouth and Earl of Doncaster. On marriage he and his wife were also elevated in the Scottish peerage to the dukedom of Buccleuch and earldom of Dalkeith. After Charles's death in 1685 Monmouth (a staunch Protestant) made the fatal error of leading a rapid rebellion against his Roman Catholic uncle, James, Duke of York, who had succeeded as James II. This was defeated at Sedgemoor, Monmouth was executed and his English titles forfeited. His widow retained the Scottish ones in her own right, remarried in 1688 and lived to 1732, but of their seven children only James (the second son) and Henry, (the third, later 1st Earl of Deloraine) survived Monmouth. Little is recorded of James. In autumn 1692 at the cross of Sanquhar, Dumfries, '30 or 40 wyld people' (without his knowledge) embarrassed him by proclaiming him King of Britain and in January 1694 he married Henrietta, daughter of Charles II's celebrated friend, the witty Laurence Hyde, 1st Earl of Rochester. Their eldest son, Francis, subsequently became 2nd Duke of Buccleuch.

This miniature, formerly in the Buccleuch collection, was therefore perhaps a family piece. It is one of a group purchased from it for the Museum by Sir James Caird in 1941 but apparently, despite the inscriptions, in confusion with a rather similar Buccleuch one of Admiral Sir Charles Wager which Caird did not acquire: it is listed as Wager by 'L. Crosse' in Caird's purchase record of the group. Based on the sitter's apparent age it probably shows Dalkeith about the time of his marriage in the mid-1690s.