Edo period (1615-1868), 17th century The russet-iron helmet constructed of eighteen vertical plates with standing flanges, the surface of each plate decorated in silver hirazogan with scrolling vines and ginger roots, and the outline of igaki running along the koshimaki, the mabizashi inlaid with clouds, the crown fitted with a two-stage silver and gilt-copper tehen kanamono carved with vines, the bowl mounted with a five-lame solid-plate shikoro lacquered black, trimmed on the lowest lame in horse hair and laced in sugake style in brown silk, the fukigaeshi applied with silvered-metal heraldic crests and trimmed in gilt-metal fukurin, fitted with a maedate of a bonji before a gilt-silver disc encircled by a ring supporting flame in red-lacquered metal 7 1/4in (18.4cm) high, the helmet bowl only