Robert Perceval Graves

Robert Perceval Graves (9 March 1810 in Dublin – 5 October 1893 in Dublin) was an Irish biographer and clergyman, brother of both mathematician and bishop Charles Graves and jurist and mathematician John T. Graves. He was a brother-in-law of the German historian Leopold von Ranke who was married to his sister Helena Clarissa, and an uncle of the poet Alfred Perceval Graves. Graves is best known for his three-volume biography of W. R. Hamilton. Provided by Wikipedia