Muromachi period, early 16th century AD
The sujibachi-type helmet was constructed from a number of vertical plates rivetted together. Each plate was turned up along the long edge to form a strengthening ridge, or suji. The iron was 'russetted', that is, deliberately rusted to a deep patina which prevented further rusting. The shikoro, or neck protector is articulated to allow the arms to be raised above the head. The crossed hawks' feathers are a mon, or clan badge.
Other types of helmet from the Sengoku jidai ('Period of Warring States' from the mid-fourteenth century to 1600) include the hoshibashi which is covered with short protruding spikes and which originated during the Heian period (AD 794-1185).
The helmet is signed by the armourer Katsuyoshi of the Myochin school.