Devices and badges form a branch of heraldic study, the importance of which has not been sufficiently appreciated. It is of the greatest value to the archaeologist, in helping him to ascertain the origin and fix the date of an infinity of works of Art. The knight bore his device upon various parts of his dress; it was embroidered upon his surcoat and on the caparisons of his horse ; it was engraved upon his armour and his arms, inscribed upon his objects of daily use, his books, his plate, his bed, and his household furniture. On Majolica ware we see painted the devices of the dukes of Urbino, and those of the Medici popes appear in the Loggie of the Vatican.