The usual form of helmet in the twelfth century is the cup-shaped headpiece of which the Cervellière is a typical example (Fig. 7). It was either worn as the sole defence or was used in conjunction with the helm as anunder-cap. The wide-rimmed hat of iron is found all through the period of defensive armour with which we deal. It appears in the thirteenth century (Fig. 8) and is also to be found in the fifteenth. There is an example of one of these war-hats (Eisenhut) in the museum at Nuremberg. FIG. 6. Detail from the brass of Sir Roger de Trumpington, Trumping-ton, Camb., 1290. FIG. 7. From the monument to Johan le Botiler, St. Bride's, Glamorganshire, 1300. FIG. 8. Add. MS. 11. 639, f. 520, thirteenth century. The Shield at the time of the Conquest was kite-shaped. It was long enough to cover the body and legs of the warrior when mounted, but it must have been a most inconvenient adjunct to his accoutrements. As we have seen in the Monk of St. Gall's records, the shield was sometimes made of iron ; but the more usual material was wood covered with leather or the tough cuir-bouilli. Its broad flat surface was from the earliest times used by the painter to display his art, which at first was not systema-tized, but consisted of geometrical patterns and strange birds and beasts that had no special meaning. As time went on each knight retained the device which was borne upon his shield and came to be recognized by it, and from this sprung the complicated science of 28 THE AGE OF MAIL CHAP. I