Japanese Armor of the 1200s to Early 1500s
Three varieties of armor were common on the battlefields of the thirteenth to early sixteenth centuries. During that time, most battles were fought as skirmishes between mixed forces of cavalry and infantry. The armor worn by these warriors differed by role, but it typically consisted of a cuirass (chest guard), shoulder guards, thigh guards, and helmet, all reinforced with hundreds to thousands of interlaced strips of toughened leather or iron.
Armor of this type was light enough to be carried by the small-statured horses of the time but strong enough to protect from arrows, the primary weapons of the period. Centuries of gradual improvement made the armor lighter, stronger, and more comfortable to wear, but the basic design remained consistent until the mid-1500s, when firearms were introduced from Europe. The arrival of that deadly new technology forced changes in the design of Japanese armor and forever altered the methods of warfare.
Leather and fabric are easily destroyed by fire or exposure to the elements, and complete suits of armor from this period are extremely rare. Much of the armor that survives today was safeguarded by Buddhist or Shinto institutions such as Kasugataisha Shrine. Shrine collections of armor, weaponry, and other artifacts are therefore important records of warrior culture and technology.
Ōyoroi
Ōyoroi armor was worn by high-ranking warriors who fought on horseback using bows and arrows. The armor is designed to accommodate the motion of drawing and firing a bow. The chest guard wrapped around the torso, joining under the right arm, and the resulting weak point was covered by an underarm guard called a waidate. A mounted archer wearing ōyoroi was therefore most protected on the left side, which faced toward the target when firing. Two additional pieces covered gaps at the sternum and upper chest.
Ōyoroi armor can be identified by its boxy design and four-section skirt, which only partially covered the inner legs. As the armor of elites, ōyoroi often had elaborate ornamentation. Even after it was replaced on the battlefield, ōyoroi continued to be worn by high-ranking warriors in ceremonies and processions as a sign of status.
Dōmaru
Dōmaru armor was developed as infantry came to play a more central role on the battlefield. The armor was lighter, cheaper, and allowed more freedom of movement. As with ōyoroi armor, the dōmaru chest guard was a single piece that wrapped around the torso and joined under the right arm. But unlike ōyoroi, the armor overlapped, leaving no vulnerable openings. Dōmaru armor also had several hanging sections (called tassets) that provided fuller coverage of the thighs when compared to the four-section design of ōyoroi.
As armor for rank-and-file infantry, dōmaru was commonly worn without shoulder guards or a helmet, and it typically had fewer protective strips of leather or iron. Gradually, even high-ranking warriors came to favor the extra mobility of dōmaru, which led to a hybrid design known as dōmaru-yoroi.
Haramaki
Haramaki armor was even lighter and cheaper to produce than dōmaru, and it became the default armor of low-ranking infantry after its introduction in the early 1300s. Like dōmaru, the haramaki chest guard was a single piece that wrapped around the body, but it tied together at the back rather than below the right arm. This difference is the major distinguishing characteristic of haramaki.