One of several portraits of Henry St.John, 1st Viscount Bolingbroke, held by The National Portrait Gallery. Their collection includes both oil portraits and engravings of Bolingbroke.
Oil on Canvas 5.72cm X48.3cm
The NPG website states that the attribution cannon be regarded as certain and states that Bolingbroke probably sat for Richardson in 1732 and did so three times in 1738.
See 'The Iconography of Bolingbroke' by Mr F. T. Smallwood, Report no 10 Friends of Lydiard Tregoz, 1977.