Dahl was a Swedish painter who studied under Ehrenstrahl (see 405909) before coming to England in 1689. He was patronised by Queen Anne, painting some naval portraits for her (subsequently given by George IV to the Greenwich Hospital and now in the Maritime Museum) as well as the three works still in the Royal Collection.

This portrait was bought by George III from a certain Mr. Carter, boat-builder at Eton, for four guineas in 1805 as a portrait of the Duke of Marlborough. This happy find is probably not of the Duke of Marlborough but is almost certainly by Dahl dating from 1690-5. The sitter could be a member of the family of Frederick, Duke of Schomberg (1615-90), but cannot be identified with any certainty.

The sitter is an officer, wearing a red coat with breastplate over it, a sash with gold fringing at the waist; right hand holds a baton, the left on his sword hilt; a cavalry action appears in the left background.