The Samurai Armor History, Evolution and Types explained

Samurai armor has been a symbol of Japan's samurai culture and artistic sensibilities for centuries. The samurai culture, things like katana sword and samurai armor, have heavily influence on the western pop culture, a good example is the Star Wars, we can see Lightsabers, The way they are used, and the significance placed on them, mirror the samurai's spiritual connection with their katanas, The design of Darth Vader's helmet has been widely noted to resemble a samurai kabuto helmet. And the movie “Last Samurai”, the red armor set Tom Cruise wear is certainly a dream for every boy, and men.

While many people appreciate the striking look of samurai armor, they often overlook the rich history and variety of styles behind it. The armor isn't just about visual appeal, but also reflects a deep cultural heritage and diverse adaptations for different battlefield roles. To fully appreciate samurai armor, it's essential to look beyond its cool exterior and understand the story it tells about the past. This article will introduce the history and development of Japanese armor.

Table of Content (By Types of Japanese Armor)

• Tankou 短甲
• Keikou 挂甲
• OYoroi (大鎧)
• Doumaru, Haramaki, Haraate (胴丸・腹巻・腹当)
• Tosei gusoku (当世具足)
• Difference between each type

The beginning:

Yayoi Period (300 BCE to 300)

In this period, Japan is still moving from New Stone Age to Iron Age, the use of iron is still very rare. Japanese armor in this period is pretty simply, mainly made of leather and wood. These armors provide limited protection, but consider the weapons used in this period are simply bronze swords, bronze pike, these armors will get the job done.

Kofun Period (250 to 538)

In Kofun Period, Japanese culture and technology have significant advancements. Warfare during this time would have likely revolved around territorial disputes and power struggles among these clans, as well as defensive actions against Invasion from the mainland. soldiers were typically armed with straight iron swords (chokutō), as well as spears and bows. The majority of combat would have likely been hand-to-hand, but archery may have also been important

In the areas of weapon and armor production, we can see Iron Swords start to replace bronze swords, they are straight, double edge, the sword design is heavily influenced by China and Korean peninsula. And for armor, 2 important types of armors were invented in this period, they are Tankou and Keikou:

1- Tankou 短甲

The “Tankou” is a type of body armour made of iron or leather plates, sewed together with rivets or leather. The name Tankou in English literally means “Short Armor”, covering the chest and abdomen, and it’s possible origin from the Korea Tankou.

Generally, it is opened and closed using a hinge on the right side and adjusted on the front side.
The oldest “Tankou” found in Japan was found in the Iba ruins in Shizuoka. It is thought to be from the Yayoi period and is made of wood.

2- Keikou 挂甲

The “Keikou”, translated to English means “Hanging armor”, is another type of body protection made by sewing small plates of iron or leather called “kosane” together using leather or threads, The keikou was more elaborate, covered the entire body, similar to the lamellar armor found in other ancient cultures. It is thought to have received a lot of influence from China.

The method of binding the “kosane”s to make the armour was kept and used for later types of Japanese armor OoYoroi, we could find some similarity in these two armors.

Heian Period (794-1185)

Heian period is s considered the peak of the Japanese imperial court and famous for its cultural achievements, particularly in literature and the arts. The Samurai class started to rise in this period, Samurais are essentially professional warriors, they dedicated their life to battle and honor. In Heian Period, we can see mounted battles became increasingly important, and many battles were essentially clashes of horse-riding archers. The samurai would engage in individual duels (一騎討ち ikkiuchi) , a form of combat that emphasized personal skill and honor rather than large-scale strategy. Bows (yumi), Spear (yari) are the main choice of weapon in battle field, and we can start to see the rise of Tanto sword in Heian Period.

3-OYoroi (大鎧)

Armor evolved from the keikou to the Ooyoroi in Heian period. Ooyoroi, means the “great armor”, is the armor most people could picture when they think of Japanese armor. The iconic colorful, lacquered armor body, the eye catching helmet decoration, the “oversized” shoulder protection. Oyoroi is armor designed for mounted battles, mainly for archery. We can see some distinctive features on Oyoroi, some might seen straight at first glance, but if you understand the purpose of Oyoroi under the history context, you will start to appreciate the beauty of the Oyoroi design.

Let’s start from Kabuto (helmet) to understand some samurai armor parts that's unique to a Oyoroi:

Fukikaeshi (吹返）

The rolled plate on the front part of the helmet is called Fukikaeshi (吹返), Fukikaeshi in Oyoroi is clearly larger than Japanese armors in other periods. The purpose of Fukikaeshi is to deflect arrows from the side, as well as provide extra protection to the clavicle part.

Kote (籠手)

Oyoroi in Heian period only has left hands’s Kote (arm protection), because you need to use your right hand to draw the bow. In Japanese (related to Oyoroi), the left hand is called horse hand, and right hand is called shooting hand. Right hand usually in well decorative silk cloths.

Do - 胴

Do is the chest armor in Japanese armor. In Heian Period’s Oyoroi, a leather piece known as ‘tsurubashiri-gawa’(弦走韋) is applied from the front to the left front of the Do. This leather piece, serves to prevent the bowstring from catching on the small metal scales ( 小札 kozane) when the bow is drawn, this piece is usually with decorative drawing that reflects the owner’s family, or personal taste.

Another distinctive feature of the Oyoroi’s Do is the 'sendan ita' (栴檀板) and 'kyūbi ita’(鸠尾板) , the two plates installed at the chest position. The larger 'sendan ita' is located on the right chest and usually features an exposed plate style. The smaller 'kyūbi ita', on the other hand, often adopts a style similar to the 'tsurubashiri-gawa'. These two plates are mainly made of iron, cowhide, and deerhide. The tops of these two armor plates are connected to the main body of the armor. The 'kyūbi ita' is used to provide protection for the left chest when shooting arrows, while the 'sendan ita' is used to protect the right chest when the right hand is wielding a weapon.

Sode (袖)

On the left and right shoulder areas of the armor, there are two perforated armor plates, called 'Shoji no Ita ’( 障子板). These are designed to prevent the armor cords from being cut by the string when the warrior draws the bow.

Thigh Protection

In Heian Period, Oyoroi doesn’t have thigh protection (Haidate) because it will make riding horse uncomfortable.

Nanbokucho period (1336- 1392)

This is the time of intense conflict in Japan. The period's name, which means "Northern and Southern Courts," refers to a civil war between two imperial courts: the Southern Court, led by Emperor Go-Daigo and his descendants who sought to reclaim autocratic power, and the Northern Court, backed by the Ashikaga shogunate that wanted to maintain the shogunate system.

We will see less individual duel, and more large scale battles in this period. The weaponry and armor of the Nanbokucho period were similar to those of the preceding Kamakura period. Swords (tachi, katana), polearms (naginata, yari), and bows (yumi) were the primary weapons used by samurai. The ō-yoroi was still in use, but there was a shift towards lighter, more flexible types of armor, like the Doumaru and Haramaki, better suited for infantry combat.

4- 胴丸・腹巻・腹当 - “Doumaru”, “Haramaki”, “Haraate”

The “Doumaru”胴丸 was the set of armour used by lower and middle class samurais.

During the Heian period when wars were mainly bow and arrow wars, these samurais would walk and fight on foot instead of riding a horse. They would wear these “Doumaru” which were lighter than “Ooyoroi” making them more agile.
Later, approximately around the Nanbokucho period, wars changed into bigger scale fights using weapons such as Japanese swords, polearm like “Naginata”. This change led to high class samurais to also wear these “Doumaru”

The “Haramaki”腹巻 is worn by putting yourself inside the suit from the back before creating a knot to close it.

At the beginning, it was mostly used by lower class samurais. The “Kusazuri” protecting the lower body was made of 7 layers that would each be slightly lower than the previous to increase mobility. The whole suit was also lighter than the “Doumaru”. Similarly to the “Ooyoroi” and the “Doumaru”, with time, the armour changed so the weight would not only be on the shoulders but also distributed to the waist. This caused the curves near the waist to become more apparent.

To block the openings in the back, a plate called “Seita” was used. From the Muromachi period, more and more high class warriors started using the “Haramaki” as well as the “Doumaru”. In these cases, big sleeves were worn together.

The “Haraate” 腹当 was the simplest of Japanese armor and was used by the poorest of soldiers as it only protected the chest, stomach and both flanks. Higher class warriors would wear them as light fighting gear under their clothes. It is said to have existed since the Kamakura period.

Sengoku period 1477-1573

Sengoku period also known as the "Warring States" period, was a time of near-constant military conflict, This period was marked by social upheaval, political intrigue, and continual warfare between competing regional lords known as daimyō.

The Sengoku period saw the introduction of firearms, specifically matchlock muskets, to Japan. These were initially imported from Portuguese traders and then produced domestically. The use of firearms changed the dynamics of warfare significantly, from one centered on skilled individual combat to more organized group tactics. Samurais are still an important role in battlefield, but we can see a shift from individual samurai valor to the importance of coordinated infantry units (Ashigaru 足軽), who also became equipped with spears, bows, and firearms.

Gusoku represents the culmination of the development of Japanese armor, thus inheriting the good characteristics of Oyoroi, but at the same time, it also has many breakthroughs. The design intention of the gusoku was to serve as armor for infantry combat, so the importance of defense and mobility was more important than decorative considerations. The development of gusoku reached its peak in the Azuchi-Momoyama period and, as robust and durable armor for actual combat, it became the mainstream at the time. During this era of warring states competition, various complex styles were also developed. With the acknowledgment of gusoku by high-ranking samurai, a portion of the gusoku gradually evolved to a luxurious and decorative direction. Various styles of Maedate, Wakidate also emerged, adding a splendid spectacle to the chaotic world of this warring states.

5- Tosei gusoku (当世具足)

Tosei gusoku means “Modern Armor” in English, technically speaking, in Sengoku period, they should be called “gusoku” only, Tosei gusoku is a term used in Edo period, gusoku before Edo Period should be called “Mukashi gusoku” 昔具足, means old armor.

Strictly speaking, Tōsei-gusoku (modern armor) is a variant of the Doumaru, but its material and design exceed the original. Compared with previous types of armor, gusoku is lighter and sturdier. This design facilitates body movement and effectively engages in combat and pursuit. Samurai and soldiers born in times of chaos all have a strong desire to become famous. Therefore, the variety of Japanese helmets and armors became increasingly diverse, especially the decoration of the helmets which changed with each passing day. Due to individual religious beliefs and personal preferences, a variety of Maedate, wakidate appeared, which were unprecedented.

In addition to the improvements in the armor itself, another external factor that spurred the rapid advancement of armor manufacturing technology was the collision of Eastern and Western cultures. Since the 15th century, Western Europe entered the Age of Discovery, and their footsteps finally reached Japan by the end of the 16th century. In addition to religious beliefs, Western technology was also introduced to the East, the most important introduction is the matchlock gun. Therefore, armor also had to be able to resist the power of matchlock guns. Some armorers successfully made armor that could resist the shooting of matchlock guns. There also appeared new types of armor imitating the form of Western plate armor, which were generally referred to as 'Nanban-gusoku'. 'Nanban' was what the Japanese called Europeans at the time, so 'Nanban-gusoku' means 'Western armor’.

Edo Period (1603-1867)

Edo Period also known as the Tokugawa period, marked a time of peace and stability after the end of the tumultuous Sengoku period. The establishment of the Tokugawa shogunate ushered in a period of relative isolation from the outside world and an emphasis on the arts, culture, and consolidation of the samurai class.

Armor during the Edo period evolved significantly as it transitioned away from the functional and towards the ceremonial and decorative. Armor was elaborately designed and often highly decorative, reflecting the status and power of the samurai who wore it. Many Oyoroi elements are added to modern armors solely for decorative purpose.

For example in the movie The Last Samurai, We can see large Fukikaeshi (吹返), ‘sendan ita' (栴檀板) and 'kyūbi ita’(鸠尾板) on a Tōsei-gusoku, this is a typical Edo Period armor because these elements are no longer useful in modern warfare.

The Difference between each type of Samurai Armor

We've introduced the types of samurai armor, but it's natural to feel confused since they may still appear quite similar. To help you better distinguish them, we've summarized the key differences between each type of samurai armor below:

Oyoroi:

Oyoroi is large armor with extensive protection, most noticeable features are the  large sode (shoulder guards) and fukikaeshi (helmet flaps). Because Oyoroi was designed for mounted archery, we can see specialized features like 鳩尾板 (kōbi-ita, a protective plate for the chest), 栴檀板 (sendan-ita, shoulder straps), and 弦走 (tsurubashiri, string runners). Oyoroi has 4 sections of Kusazuri.

Domaru:

Domaru is fastened at the right side, offering better mobility compared to Oyoroi.
It has 8 sections of kusazuri for enhanced movement.

Uses 杏葉 (gyoyo) as small shoulder protection instead of the larger sode.
Typically not worn with a helmet or additional head protection.

Haramaki:

Haramaki is worn by wrapping it around the body from the back and fastening it at the back. It features 5 to 7 sections of kusazuri.

Haraate:

Provides limited protection, covering only the front and a little of the sides, with no back protection. It features 3 sections of small kusazuri.

Tosei Gusoku:

A fully armored suit, incorporating all protective parts, including unique maedate (front crests) and wakidate (side crests) on the helmet.

Offers the best protection and good mobility, representing the evolution of Japanese armor for comprehensive defense. 

Samurai Armor Components: Included vs. Excluded by Type

As we trace the journey of these armors, it becomes clear that they were not just protection for the body, but also expressions of the soul. The shifting aesthetics, materials, and designs reflect not only the changing facets of warfare but also the evolution of the Japanese culture, societal values, and artistic sensibilities.

While the era of the Samurai has passed, their legacy continues to live on in these armors. Each piece of yoroi, each Kabuto, bears silent testimony to the stories of courage, honor, and duty that shaped Japan's history. We hope you will find this article helpful, and thanks for joining us.