Yumi (弓) - The Japanese Bow

Wakyuu (和弓) - The Japanese Bow

DISCLAIMER:

Since the article is longer than the expectations, here is a little Index:

- History: Different bows structure and composition from the Yayoi to the Edo Period

- The asymmetry, length and draw techniques explained

- Power and range: Draw weight estimation, maximum range recorded and other sources

- Arrows and quivers: Arrows types and quivers types

- Bow & Armour: Some estimations and accounts

Have a nice reading!!

                                        

         A copy of the famous Mouko Shurai Ekotoba  蒙古襲来絵詞

History & Structure

The Japanese Bow or Wakyuu (和弓), also called Yumi (弓), is one of the most interesting weapons used by the ancient Samurai warriors, but its history is even more older. Like in many countries, bows were tools for hunting before being weapons, and Japan was no exception.

Stone arrowheads unearthed by archeologists suggest that bows and arrows have been used in Japan from as far back as 10,000 BCE, and it was used indeed as a weapon by the Yayoi period (c.300 BCE–300 CE), when fighting and war became frequent and widespread.

Early bows were quite simple; they were called Maruki (丸木) and were made of plain wood like atalpa, zelkova, sandalwood, yew or mulberry and were lacquered or wrapped with bark thongs, to increase their durability in the Japanese climate. They were also straight bow.

                                     

                     A Maruki Bow from 弓箭圖式 

This kind of bow weaker compared with later design, but it was also easy to drawn and quite effective in short distances and fast pace engagement: this is basically were the idea of Yabusame came from, in fact this kind of bows were still used for ceremonial and competitive archery, for hunting, for some kinds of training, and even on the battlefield throughout the medieval period and beyond.

There are a lot of religious and mystical stories around bows, like the Hama Yumi (破魔弓)
The grip, as noted in the Chinese Book of Wei (魏書) of the 3th century, was already asymmetrical, even before the development of the horse archery style of combat of the early Samurai. 

Composite "recurved" bows like the one used by the Mongols were known in Japan at least since the 9th century. However, horn and sinew were quite rare in Japan: cattle weren't common and handling leather or slaughter animals was a taboo in a Buddhist society, so they turned to the material they had in abundance: namely bamboo and wood.

Entering the 10th century we have the first composite bow, and the first clear evidence of this kind of structure is inside a poem by Minamoto Yorimasa (1104–80).
These bows were called Fusetake (伏竹弓) and featured a single strip of bamboo laminated to the outside face of the wood (usually yew - kaya 榧 ), using a paste (called nibe) made from fish bladders. This was done to obtain the power needed in a war bow while retaining a cross section of reasonable proportions. In this period, the familiar structure of the Waikyuu started to emerge.

Composite bows made of bamboo and wood, from 弓箭圖式

Sometimes later, in the late Heian period, bows took another step further in their development; around the 12th and 13th century, a second bamboo laminate was added to the inside face of the bow, to create the Sammai Uchi Yumi (三枚打弓) and increase its power even more.

Is not clear also when the shift from the straight (or slightly curved structure) to a "recurved" ones happened; some historians argued that based on artist depictions, only after the Mongol invasion the Yumi became a recurve bow ( meaning a bow in which the tips of the limbs curve away from the archer) but is quite hard to tell from those kind of depictions because the bow is not unstrung; so it's possible that this change was done even before.

The bows were steam-bent into arc shapes and strung against their curves, an innovation that greatly enhanced their power, and is well accepted that from the 14th century onward, the bow was a recurved one.
In the 15th century two additional bamboo slats were added to the sides, so that the wooden core was now completely encased, producing the Shihouchiku yumi (四方竹弓).

 The final step was taken around the 17th Century, in the Edo Period, where the Higo Yumi (弓胎弓) was born. This has core of three to five bamboo slats, with additional bamboo facings laminated to the front and back edges, and strips of wood laminated to the sides.

Composite bows made of bamboo and wood, from 弓箭圖式

Another interesting and rare type of Wakyuu is the Tekkyuu (鉄弓), a steel bow. This bow was made of spring tempered steel, which allowed the bow to flex and return to its original shape. Those bows were never common to begin with, due to the massive strength required to use them and to the resources used to make them, and were more ceremonial objects than weapons.

The first steel bow, most of the time simply called iron bow, was excavated from a Kofun of the 4th century, although it is highly unlikely that said bow was spring tempered, since I'm skeptical that in those days they had the technology to produce such a big mono high carbon steel bar and spring tempered it properly.

An iron bow is associated with the 16th century period myth of the hero Yuriwaka (百合若大臣).

It is established that by the 16th century, the Japanese knew spring tempering; this is also in line with their development in steel and iron industry of this period.
According to the Intoku Taiheiki (陰德太平記) of the late 17th century (published in the early 18th), Takeda Mitsukazu (武田光和) used such a bow in the early 16th century.

There is also a tekkyuu in the Edo period book Jitsu go hariyumi no zu (拾五張弓之図), and a real example preserved in the Tokyo National Museum made by Aoki Kiyohide (青木清秀) in the early 19th century.

All the Wakyuu were lacquered ( the most common color pattern was vermilion and black) to protect the glued joints from moisture, which could cause the bow staves to delaminate or lose springiness and then bound with thongs of rattan, birch bark or silk.This bindings, other than holding the bow, served as sights; you could estimate the distance between the bow and the target and aiming accordingly.

Bowstrings, Tsuru (弦), were generally made of plant fibre, usually hemp or ramie, coated with wax to give an hard, smooth surface.
An additional bowstring was carried around the waist, near the swords, in the early times.

     

   Tsuru from 弓箭圖式 

Japanese warriors were really found of their bows; in the early period, the term "Kyuusen no Ie" or "Yumiya no Ie" (弓矢の家) meant Samurai family, although the right translation is "Bow and arrow family", and being able to shoot a powerful bow was sign of martial prowess.
Most of the time the fight was carried by noble "Bushi", whom fought archery duels on horseback, at least this is what emerges from the Gunkimono (軍記物). After the rise of the infantry soldiers in the late 14th to 15th century, bows were still in use on foot, both by Samurai and by Ashigaru, which used the same kind of bow. It is actually true that Japanese warriors, in basically any kind of period, were archers before anything else.

Even if not as before, a lot of people underestimates the role of this weapon; from the Heian up the Muromachi Period, the Wakyuu remained the top killer, causing the 82% of total wounds in 14th century alone.
Even when matchlocks firearms started to widespread in Japan after the 1560, bows were still used in huge numbers, and arrows wounds were the second most common type of injury ( 45% for arquebus, 21% for arrows).
Also bows, although they required a lot more skill to be used, have more range, accuracy and a faster rate of fire than early guns, not to mention other factors like rain or mud which make guns even less effective.

Some early forms of Kyuudo, from 千代田之御表

Shape, Grip & Length -Why the asymmetry and the "huge" length?

The Yumi is the largest bow in the world; if you are wondering why these bows were as long as 2,7 meters, well the answer is quite clear, and is a similar answer to why English Longbows are "long" too.
Simple wood bows will not bend very deeply without breaking, and overflexing composites of wood and bamboo stresses the adhesive and makes the laminations separate. To achieve significant power, therefore, wood or wood and bamboo bows must be long, sometimes even as much as 2 meters, which was quite the norm for any Japanese bow.

And this led to another important point: why the grip is asymmetrical?
Some historian argued that due to the length of the bow, the grip has to be like this to be effectively used on horseback, and this seems reasonable but the grip was already asymmetrical before any significant development in horse archery warfare, and even when horse archery wasn't practiced anymore on the battlefield, the grip was still there.

Other scholars argue that the lopsided proportions were originally necessary to balance the bending characteristics of the wood: simple bows, produced from a single piece of wood, were made from young trees, using the root end of the tree for the lower part of the bow stave. The branch end of the tree is springier than the root end.
Thus the grip needed to be located closer to the bottom of the bow ( the stiffer end of the wood ) in order to balance out the elasticity of the weapon, so that it would draw evenly, without over-stressing either end.

Gripping the bow two-thirds of the way down its length maximizes its rebound power and minimizes fatigue to the archer far better than the more familiar centered grip. Careful analysis of the mechanics of a bow pulled to full draw and released shows that the Japanese grip places the archer’s hand at one of two nodes of oscillation during the shooting movement, which means that little shock is imparted to the left (gripping) hand and arm when the string is released.
Instead, using the grip in the centre puts the gripping hand at a point of maximal oscillation.

 A detail from the 男衾三郎絵巻

And this bring us to the last point; the draw length: traditional Japanese archery could reach a draw length of 1 meters more or less, and when looking at early Samurai depictions we see warriors holding the string further than the ears, which means around 80 cm to 100 cm; a lot of power indeed.
Like in many Asian countries, the Japanese drew the string with the right thumb hooked under the arrow and locked by the first two fingers resting on the thumbnail, so the arrow was positioned on the right of the bow (as viewed by the archers). To protect the hands, leather gloves were used.
There were mainly two techniques used to shoot the bow:

1) The more familiar associated with horse archery is the Ogasawara-ryu (小笠原流), in which the archer hold the bow above the head, to clear the horse, and then moved his hands apart as the bow is brought down, to end with the left arm straight and the right hand near the right hear.
However, it is not clear if this procedure called Uchiokoshi where the bow is raised above the head was used in the early periods; it might be a late Edo period invention, to allow the right sleeve of the kimono to fall down while shooting a bow.

2) The alternative method which was used on foot is quite similar to western archery, and is associated with the Heiki-ryu (日置流); the draw was begun with the bow held perpendicular to the ground.

To release, the fingers supporting the thumb were relaxed, allowing the string to slip off the glove and allowing the bow to rotate in the hand.

Before and after the release in Yabusame, from 元文三年高田馬場流鏑馬之圖.

Power & Range - How strong it was?

After the previous reading is quite clear that bows were quite different from a time period to another, due to structure and usage.
But one of the most huge misconception about Samurai is based on their bow's power. Around the internet, especially in the "latest times" a lot of people tried to figure out the power of the Japanese bows, and a lot of them was looking for the infamous "draw weight".
Until very recently, actual data on historical draw weight weren't available and this lead to the idea that said bows were relatively weak; nothing more far from the truth! (more on the EDIT).
So, short answer: it was powerful as much (is not even more) than the majority of war bows used on the world.

Now, many people stated that the Yumi was a weak bow, weaker than the Longbow for example, mainly for these reasons:

- They got confused with Kyuudo bows, which draw weight is in between 25-66 lbs ( 11 - 30 kg circa) which is extremely low compared with war bows like the English one ( up to 180 lbs).
- They think that since it was used mainly for horse archery, it has to have a low draw weight

- Due to the emergency of Yabusame ( so short range and fast shots = low draw weight)

Well, is quite obvious that Kyuudo bows and War Bows are two completely different things, and also that Yabusame was more related to the usage of Maruki Bow rather than other proper war bows; in addition to that, Mongols and Turkish warriors, which were famous for their horse archery skills, used bows well behind the 100 lbs ( 120-160 lbs) and the Wakyuu wasn't only used on horseback!

Is quite hard to establish the draw weight of Yumi; nobody apparently bother to measure an antique bow until recently (however there are modern historically accurate replicas made with traditional techniques which are around the 110 lbs spot).
Mainly because the power of the bow in Japan was established by measuring the dimension of the core or by counting the men needed for string the bow something like a Sannin-bari (三人張り= 3 men bow) or Yonnin-bari (四人張り= 4 men bow) in ancient times.

Some researchers have tried to establish the correlation between men bow and kilograms  and they have proposed that something like a 5 men bow would be the equivalent of 70-80 kg (176 lbs).
Some chronicles mention things like 10 men bow, but I seriously doubt that would have ever been practical.

A three man bow (三人張り) from 男衾三郎絵巻

I've seen physician, historian and bowyers opinions and the draw weight range estimated is from 70 to 200 lbs, with an average of 120 lbs.
Well this is an estimation, but is also true that is not that hard to reach those numbers: you just need to add more bamboo and made the core thicker, and here you are; at the end of the day, the strength of the bow is deeply related to the strength of the archers.

EDIT: An actual historical yumi was measured in its draw weight. It was a "3 men bow" from the early Edo period, with a structure fairly similar to the ones used in the Sengoku period.
Said bow measured 196 lbs (89kg); this allowed the researcher to conclude that the idea of anything above 5 men bows were likely terms used to express power around 200 lbs, because more than 3 men cannot string a bow without hinder themselves in the process.

A screenshot taken from the video were they tested few 110 lbs bows and measured such beast.

So I'm quite happy that at the end of the day, my educated guess were not that far! END EDIT.

Now, the are some Chinese Sources that highlight the power of the Wakyuu in the 16th century (Sources via : Great Ming Military, which is a nice place where to spend some time by the way):
Ming Dynasty didn't bother to compare the strength of the Japanese bows with the ones used by the "nomads" ( Mongols) and also highlighted the fact that their arrows were heavy, deadly and capable of piercing houses from the roof to the rafters.

   
 A detail from a battle scene of  春日権現験記 (第２軸)

And that's actually the average range for bows designed to pierce armor; in fact from art depictions (both in the west and in the east) we see archers holding the bow perpendicular to the ground, to shoot straight.

There are also some legend involving an herculean Minamoto Tametomo (源為朝), who was able to sink a Taira Ship with his bow only; while this is indeed pure fantasy, nobody would have bother emphasize such a weapon if it wasn't powerful at all, nor wear heavy and thick lamellar armor.

In addition to that, the bow has a recurved and laminated structure, with long draw length and shoot heavy arrows; all hints that suggest that the Yumi was a powerful bow indeed.

Now, as far as the range is involved, there are a lot of misconception too. It is true that the Wakyuu was a specialized, short ranged weapons due to the fact that his role was trying to get through armor. This is why it shoot those heavy long arrows, which are not efficient for long range shooting. However I think that the word "short" has to be explained more.

The record for a Japanese Yumi in the Toushiya (通し矢) competition was 385,5 meters ( the record for Longbow & flight arrow is 315,33 meters ).

This was indeed possible with lightweight flight arrows, not meant to be deadly. At that distance the killing potential of the bow would have been minimal.

However it is reasonable to assume the fact that on the battlefields, the Yumi could reach 150-200 meters with the lightest war arrows quite easily and more or less 100 meters with the heaviest ones.
Again, quoting some Chinese Sources, from Song Dynasty Liang Wài Dài Dá (嶺外代答), a Japanese bow from late Heian or early Kamakura period bow can propel a fletchless arrow to a range of 100 Chinese paces (~163m) without the need of arching the shot!

The famous Battle of Crecy depiction,in which the bows are held perpendicular to the ground.

It is fair however to say that this could be considered "short" when comparing the Yumi with Korean or Turkish bows, but not when comparing it to Europeans or Manchu bows.

The "myth" of the Yumi being a short range weapons came from Kyuudo data (weak bows) and by a famous complaint of Musashi who said that the bow was unsatisfactory if the enemy was more than 40m away; but he probably meant an enemy with armor (which is true for any kind of bow).

Arrows types and quivers

It would be impossible trying to show all the possible Japanese arrow shapes and tips in a Blog's article and I have to say that this is already too long; so I'll started with the shaft.
Japanese Arrows (Ya - 矢) were made with a shaft of bamboo, cut in between November and December, then softened in hot sand and straightened with apposite tools. The length varied a lot based on the periods, and were in between 86 and 97 centimeters.

There were normally three fletchings, sometimes even four and the feathers used came from eagle, hawk or crane.

The weight varied a lot from flight arrows to war arrows; the latter often exceeded 100g, arrowheads included.

The arrowheads, or tips (Yanone) could be roughly divided into three main categories, however there are some of them which are work of art, never meant to be used. The arrowheads were fitted into the shaft by a slender tang forged with the arrow. They were usually differentially hardened in the Japanese tradition, to have maximum sharpness, rigidity and power.

Narrow four sided heads: these are often squared in section and could be Yanagi (willow leaf) , Sasa no Ha (bamboo leaf) or Togari Ya (pointed) and were the most common type of war arrows. Like the bodkin type, were meant for penetration, even of armor.

On the left some of the arrows mentioned before, from 弓箭圖式 

Barbed broadhead type: also called Hirane, these are shaped like the base of a flat-iron and are flat in section with narrow sharpened edge. This style is the most common to be highly decorated.

Hirane arrows from 弓箭圖式 

Forked arrowheads: probably the most iconic associated with the Samurai, these arrows were called Karimata after their resemblance to a flock of geese in flight and were indeed forked. Most were probably used for hunting, however in the past it has been suggested that they were used to cut the fastening cords of armor; highly unlikely in my opinion, since these were protected by the armor itself. They were used to increase the chances to hit someone.

Karimata arrows from 弓箭圖式 

Some arrows were fitted with a "whistle" and were used as a form of signal:

Other arrows images, from  弓箭圖式 and  武器袖鏡. 初編

During the early periods, when archery was performed both on horseback and on foot, arrows were carried inside Ebira, a box with a grid of bamboo which gripped the heads; it was carried around the waist:

Ebira from 武器袖鏡. 初編

While entering in the Muromachi period, the Ebira was used only for travel and the Utsubo replaced it ( it was in use since the Kamakura period for hunting). The Utsubo is a tube-like quiver, worn on the back and covered with fur.

Utsubo from 便蒙古武器圖式 (2巻. )

Bow & Armor - Which one was more effective?

As I said before, Japanese archery was highly focused on armor penetration; this is the reason why heavy arrows were shoot at short ranges with powerful bows.
"Bow vs armor" is an old debate also found in Western Europe, and like in that field, we have to use Matt Easton's favorite word: "Context!".
Is really all about context.
I have to say that when it comes to Japanese armor, which is my field of "study" and the main reason why I created this Blog, I could state that it worked pretty well.
But at the same time, the Japanese bow was indeed a powerful weapon.
In the Gunkimono we read of arrows piercing more than three suit of armor at once, or "nailing" a man with his armor to his horse's saddle.

But how much truth is in there?

Mongolian armor being pierced by Japanese arrows, detail from a copy of the  蒙古襲来絵詞

To simplify all the major factors that could get into this topic, I would argue that there are more or less three big conditions to consider:

First of all, Range:

If the target is well beyond 30 meters forget about piercing any type of armor. This is probably the most important factor; you could have the most strongest medieval bow, but even wearing a thick jacket might save your life if you are out of that range, because the arrows would have lost the energy required. You'r target should be closer, the best range is within the 15 meters or at point blank, but even at 20-25 meters you could still have some chances

Than you have to consider the Bow & Arrow:
You need a powerful bow, likely to be in the 110-130 lbs spot or more ( we are talking of course of medieval bows) and a dedicated arrowhead fitted to an heavy shaft. This is why Japanese, Manchu and English longbow used these kind of arrows.

Finally, Armor:
There are a lot of things to consider here.
First of all, the "Quality": low quality munition armor could be easily pierced even by weaker bows. Munition armor used by infantry soldiers was likely to be pierced by powerful bows in the range mentioned before.
Than the "Type" of armor used.
In Japan, depending on the period, various types of armor were used, mainly Mail, Lamellar and Plate.

For Mail armor there are a lot of factors to be considered; I've already talked about Japanese mail, so I just give you my 2 cents: be it riveted, backed with gambeson and of thick-good quality rings, mail armor is likely to be pierced by war bows, especially by one as powerful as the Wakyuu. Even if it is a "weaker material" (meaning that a lot of the energy is lost on the impact since the rings aren't rigid but moves with the arrows a little bit), the arrows could pierce, break or slip through the rings and if is sharpened enough it could finish the job by cutting the layer of leather or clothes behind it.

Lamellar armor, like brigandine or similar, is still a "weaker" material (not as much as mail) but doesn't have the spaces in between rings so is less likely to be pierced; however this highly depends on the material ( hardened leather, iron or steel). There were some armor entirely made of leather lamellae which were more likely to be pierced, but even iron ones weren't 100% arrow proof: In some test done by Mori Toshio (森俊男) a Japanese bow was able to pierce 1,6 mm of steel ( the arrow speed was around 60 m/s). A close shot performed by an horse archers could have been able to get through the lamellar structure. And that's the reason why in Japan ( and other part of the world) the lamellae usually overlaps to double or triplicate the thickness.



Finally Plate; this is not a weaker material because its rigid, however the energy required to defeat those armors could be increased by creating curvatures: this is why helmet and breastplate usually have those shapes.
Now when it comes to plate, curvature, thickness and quality are the main factors to consider. Even low quality munition armor, if thick enough, could still stop war arrows without too much effort. However most of the time, the poor's Ashigaru were issued with low quality and fairly thin metal breastplates that were indeed pierced even by less powerful bow.
Yoshida Nouan ( 吉田能安)  shot a steel helmet in a comprehensive review held in Nikkou Toushouguu in 1967, with a 30kg (66 lbs) bow at 15m: it pierced the helmet side by side. The bow was still relatively weak, so the helmet must have been a really low/munition quality ones (and the archer a skilled ones).

Good quality, highly worked plate on the other hand could defeat arrows quite easily.
Sakakibara Kozan in his "Chukokatchu seisakuben" wrote of plate forged in a precise way which were arrowproof and bulletproof.

Detail from the Heiji Monogatari Emaki

Conclusion:

At the end of the day, arrows were only capable of defeating the main defense (breastplates and helmets) of low quality or "weak" armor in some conditions, but they where still capable of piercing limbs protected by less thick plates /mail of the high end example, or bypassing entirely the protection when hitting non-protected zones (most of the time leaving a non fatal injury).
However, the best equipped warriors didn't fear them at all.
It is also true that all over the world, despite armors, arrows were still shoot in huge numbers and many people died due to their efficiency at killing, especially in Japan.
The armor piercing ability was also increased in the early periods thanks to the horse archery, which allow the warrior to close the distance without risking too much.



Yes, I know, this article is Huge. But I really wanted to create an article available for everyone filled with as much content as possible.
If you have been brave enough to finish it, Kudos to you and a big thank you.

Hope you have enjoyed! If you have any comments please, feel free to express you're opinion.

Gunbai