Dorothy, Viscountess Townshend (1686–1726), was the daughter of Robert Walpole of Houghton and Mary, daughter of Sir Geoffrey Burwell of Rougham, Suffolk. Her brother was Sir Robert Walpole, 1st Earl of Orford (1676–1745), who was a political ally and then rival to her husband, Charles, the 2nd Viscount Townshend (1675–1738), whom she married in 1713. She died of smallpox in 1726. The ghost of Dorothy Walpole, associated traditionally with a spectre called 'Brown Lady', is rumoured to haunt the oak staircase at Raynham Hall.

This portrait, though signed and dated 1722 by Kneller, is not cited in Stewart’s catalogue raisonné of 1983, suggesting that perhaps he was unaware of its existence. Oliver Millar, who saw it during a visit to Raynham Hall in 1995, commented that it was ‘soft, clear, very accomplished’. RN70 was made when Dorothy’s husband was – jointly with her brother, Sir Robert – leader of the Whig party (1720–30). Several copies and versions of this portrait exist, including a version sold at auction in London in 2003 (Bonhams, 9 July 2003 [167]). There is also a similar head-and-shoulders portrait in the form of a roundel, dated 1719 (Christie’s, London, 5 February 1971 [64]). The Viscountess was also painted by Charles Jervas (c.1675–1739), including an informal likeness with her hair in a similar relaxed fashion as in the present Kneller portrait (photograph, Heinz Archive, National Portrait Gallery). She also commissioned other paintings by Jervas, as noted in the related Object in Focus study by Amy Lim in this project, ‘Charles Jervas: A Memorandum of 1733 at Raynham Hall’.