Henry David Erskine was the son of David Erskine, 9th Earl of Buchan, and his first wife, Frances, daughter and heir of Henry Fairfax, of Hurst, Berkshire. The sitter has also previously been identified as Henry David Erskine's second son, David Stewart, 11th Earl of Buchan (1742-1829), an antiquary and political reformer (see later inscription).