From being uniformly conical in shape, the skull of the nasal helmet became more varied during the 12th century. For most of the century nasal helmets with a forward deflected apex, often called the "
Phrygian cap" shape, were in widespread use. It is possible that the deflection of the apex of the skull was the natural result of making the front of the helmet thicker than the rest of the helmet during the process of raising the skull from sheet iron. Though still used, the conical type of helmet declined in popularity during the latter half of the 12th century and round-topped nasal helmets came into fashion. King
Richard I of England is depicted wearing a round-skulled nasal helmet on his first Great Seal (1189). , manuscript c. 1200 A further type of nasal helmet developed in the late 12th century. This helmet had a flat top and a square profile. This form of nasal helmet was the forerunner of deeper, cylindrical helmets with greater facial protection,
enclosed helmets, and eventually the
great helm. The existing nasal formed the basis for increased facial protection, eventually, by 1200, producing a face covering plate which was pierced for sight and ventilation. The helmet began to lose popularity at the end of the 12th century to helmets that provided more facial protection, and although the nasal helm lost popularity amongst the higher classes of knights and men-at-arms, they were still used by archers to whom a wide field of vision was crucial. Round-skulled nasal helmets can also be seen worn by a proportion of knights throughout the French
Maciejowski Bible dating to 1250. No doubt some knights preferred the better vision and hearing afforded by this more open helmet. ==Use==