 He was also a biographer, and published works on his great-grandfather, the Prime Minister the 2nd Earl of Shelburne and of his earlier ancestor, the economist, scientist and philosopher Sir William Petty (in "Life of Sir William Petty 1623 - 1687", published 1895), of the 2nd Earl Granville and of Charles William Ferdinand, Duke of Brunswick, amongst others.Moreover, he was a Trustee of the National Portrait Gallery and a Fellow of the British Academy.Published works of Lord Fitzmaurice are