Autograph envelope only, signed ‘Cambridge’, addressed by the Duke to ‘The Earl Nelson, Trafalgar, Salisbury’. 3½ x 4½ inches, black edges, ducal monogram on flap, Salisbury backstamp, slightly worn. Postmarked London 6 January 1898. George William Frederick Charles, Duke of Cambridge (1819-1904), the only son of George III’s seventh son, Adolphus Frederick. The Duke fought in the Crimea, and from 1856 to 1895 was commander-in-chief of the British Army.