The title of Earl of Devon was created several times in the English peerage, and was possessed first (after the Norman Conquest of 1066) by the de Redvers (alias de Reviers, Revieres, etc.) family, and later by the Courtenays. It is not to be confused with the title of "Earl of Devonshire", held, together with the title Duke of Devonshire, by the Cavendish family of Chatsworth House, Derbyshire, although the letters patent for the creation of the latter peerages used the same Latin words, Comes Devon(iae). It was a re-invention, if not an actual continuation, of the pre-Conquest office of Ealdorman of Devon.