The principal authority for the accurate dating and classifying of shields is the immense number of mediæval seals attached to deeds and charters, and with dates exactly known. If it were practicable to arrange in chronological sequence illustrations of a sufficient number of these, we should at once have the classification of dates, styles, and shapes, which would be so very valuable, and which it is the attempt of this paper to display. Hence it is that to the end of the fifteenth century seals form so large a part of the evidences submitted. The certainty of such records is unsurpassed: we have a parchment, itself dated, or the date of which in very early instances can be otherwise closely ascertained; and attached to this we have a seal with the shield; and, to make it perfectly certain, we have the owner's name inscribed around it, and so we know he is not using some one else's seal, found or come down to him from earlier times. Such instances frequently occur, and are at once in this way detected. There are instances where the same seal, acquired in early life, continued to be used for over fifty years; but that is the extent to which such valuable proofs can wander from the actual prevailing type and date. Besides seals, the many invaluable illuminations in the British Museum and Bodleian Libraries, and in the great Continental Libraries, furnish numberless pictures of knights and their accoutrements, contemporaneously executed, and with the most manifest exactness in every detail. Many of these have been engraved in our popular literature, as well as in the learned works named above; but to enable the mind to form correct conclusions these should be all cut out and arranged in groups of exact dates, or drawn as they are in a student's note book. The earlier monumental effigies afford many valuable examples of shields, and after they cease to be represented by the side of the figure, such often appear among the architectural details, giving the shape of shield, with an exact date attached. Monumental brasses give evidence to a later date, and the canopy work introduced often carries ornamental shields.