A great helm

A great helm, of riveted construction, conical crown formed of two plates - the front with medial ridge and lower edge slightly flared out above two vision slits, slightly domed oval top, two further plates covering the lower head and face, the front ventilated with 18 key shaped perforations and with the upper rim reduced to form the two vision slits with a vertical strap between riveted to the upper plate, height 33 cm (13 in.), in the manner of the late 13th Century but believed to be 19th Century.