The present portrait has been identified traditionally as Eleanor (‘Nell’) Gwyn (1651?–1687), actress and mistress of Charles II, who is associated speculatively with numerous portraits of anonymous young female courtesans and actresses. However, the resemblance of the present sitter to verifiable portraits of Nell Gwyn, notably those by Simon Verelst, indicates that the identification is untenable. Rather, it is suggested here, the sitter is Mary (1662–1694), eldest daughter of James, Duke of York, later James II, and Anne Hyde. In 1677 Mary married Prince William of Orange. She ascended the throne as Queen Mary II, jointly with her husband, in 1689. Comparison with a similar portrait in the National Portrait Gallery by Sir Peter Lely of Mary, aged fifteen, around the time of her marriage (fig. 1) would appear to confirm the identification.¹ The present portrait is attributed here to the circle of Lely on stylistic grounds, and on the comparison with the portrait of Princess Mary in the National Portrait Gallery.