Complete body armour called the ōyoroi ('great harness') was designed in the Heian period (794-1185) to protect mounted samurai warriors against arrows shot from the long-bow. The helmet was made of rivetted iron plates to repel sword blows. Much of the armour was designed to be very flexible to offer protection during battle. The hanging neck-guard (shikoro) and large side-flaps (fukigaeshi) protected neck, face and throat. The trunk and front of the body were covered by a cuirass and a split apron of lacquered iron plates. Large rectangular shoulder-pieces could rise and shield the exposed side when the bow arm was stretched out. Two similar flaps hung in front of the breast. Armour was often richly decorated with gilt-copper fittings and coloured silk braids. Leather, textile and lacquer was also used. During the period of continuous civil wars (sengoku jidai, 1467-1568) helmets became particularly fearsome.
The first big changes to the traditional 'harness' came with the arrival of fire-arms in the sixteenth century. Bullet-proof iron breastplates were introduced, copied from western models, and the fukigaeshi became obsolete, used only to display the mon or family crest.
During the peaceful centuries of the Edo period in Japan (1600-1868) armour became much lighter and was only worn for show when the daimyō processed to and from the capital. The short civil war at the time of the Meiji Restoration (1867-68) was the last occasion in Japan when armour was worn in battle. However, there is an ongoing programme in Japan for the preservation and reproduction of fine ancient armours which ensures that the manufacturing technology is not lost.