Oil on canvas. Edith Phelips, the daughter and heiress of Sir Edward Phelips of Montacute, married Carew Hervey Mildmay (1690-1784) in May 1744. Her husband had been Private Secretary to Henry St John, later Viscount Bolingbroke, from 1709 to 1714, before retiring from public life to live as a country gentleman. This is a companion portrait to Herman van der Mijn's portrait of Mildmay of 1733, also in the Government Art Collection (GAC 4802). The painting is a rare example of a portrait of a female sitter by John Shackleton, who was appointed Principal Painter in Ordinary to George II in 1749.
