Wantō (湾刀): Early Curved Japanese Swords

Wantō (湾刀): Early Curved Japanese Swords

A classic example of a curved warabitetō, the most common style.

If you have ever tried to approach the study of Japanese swords, you might have encountered the incredible amount of different theories and the huge (and occasionally hostile) nomenclature that pervade such field. In order to make things clear and at the same time pay omage to this long tradition, today I'm going to talk about the Wantō (湾刀), the first curved Japanese swords.
This specific name is an umbrella term used to refer to every Japanese curved swords, although in this s artilce I'm going to present the very first types of said family, namely the warabitetō (蕨手刀) which differs from the usual curved Japanese sword of the later periods and all the variations that sprung from this so iconic and yet forgotten Japanese swords.

As a premise I would love to point out that this is definitely not my area of expertise, and it tooks several month to get the puzzle more or less correct; this topic is massive and it has not been covered as much as it should by modern publications, since most of the attention is given towards later period blades.
So this article is rather an introduction on the topic, as I believe there are much more reliable and authoritative sources than me.

However, I would love to say that this article was possible thanks to the majestic work of Carlo Giuseppe Tacchini, "On the Origins of NihonTo", a paper that is the main reference for the entire article.


Before drescribing those swords it is important to briefly talk about the political situation of Japan during the Nara and the early Heain period, so in between the 8th and 10th century.
In fact, in the 700s Japan wasn't unified under a central government and the north eastern regions were independent from the Yamato court which controlled the south west of the archipelago.
The Kantō region and the entire Tōhoku region weren't under direct influence of the court and had their own unique culture. While the Kantō people were still fairly similar to the ones who inhabitated the southern part of Japan and were gradually assimilated within the Yamato sphere of influence, the north was populated by the Emishi (蝦夷), a people whom are still mysterious and highly debated among modern day historian.

                                           
                                          Emishi people from a 14th century depiction

In both regions there was a strong and vivid horse culture probably brought by Korean immigrants during the 3rd and 4th century, and the Kantō region was a source of skilled horse archers for the Yamato army.
It was within these regions and especially in the north that new swords models, native from Japan and independent from direct influences of the mainland were developed around the 5th and 7th century.

During the 8th and 9th century, the Yamato tried to assimilate both regions through political alliances, integration of these people in the Japanese society under the control of the Imperial court and ultimately through war. Those pieces of history, despite being extremely interesting, would not be covered here but it is important to highlight that it was through this contact that these types of swords spread towards the south east of the region.


Early History, V -VII century

It has been established by historians that the people in the north of Japan at the time had developed a slightly different type of iron smelting technology compared to those influenced by the mainland in the south east, and this is somewhat explained by different types of furnaces as well as different types of sword's designs.
The creation of this type of weapon, called warabitetō is dated 5th century, during the Kofun period; however, it gain popularity during the 6th and 7th century especially in the north eastern regions. Despite the fact that the people of the north had a consolidated and established net of trade with the mainland, there are no equivalent swords found there so it is assumed that it was a designed native to Japan.

The name of it is due to the fact that the hilt design which resembled a young bracken, with its iconic pommel.
These swords were quite short, in between 40 and 50 cm blade length on average and no swords exceeded 60 cm with the longest example at 58 cm.
On the other hand, they usually sport a strong  curvature; more then one hundred specimens shows curvature and about 22 show a sori more than 0,5 cm deep, ten of them even a curvature between one and two centimeters, although straigh examples along the blade existed as well.
This curvature in fact might look odd to the untrained eye, because it is emphasized along the hilt, and this tsuka-sori concerns especially early examples.

A straight warabiteto sword; notice how the curve is mainly concentrated towards the hilt, a typical feature of later Heian period tachi.

These blades were intended as a cutting& slashing weapons, and this is clearly seen along the tsuka-sori, the width of the blade around the monouchi area, and the stepped kamasu-kissaki also found on the swords used by the Yamato people.
Also, the sori of the blade increases the overall curve of the weapon, which results in a better cutting ability.
The artisans who forged these swords applied therefore consciously a sori, and the emphasis of the latter led gradually to the emergence of a tachi-sugata, and therefore the warabite sword has to be regaded in the wider sense as the first step toward this development.
In fact, the peculiarity of this early curved sword is that the curvature is mainly focused on the hilt. This offset the line that connect the blade tip with the hilt and so the blade function as curved. However, the most common type of warabite sword has a strong curvature along the blade as well.

Warabite sword with curved hilt and curved blade.

It has been suggested that the development of this curved sword was related with the strong horsemanship culture of the regions during this time. However, despite the clear advantages of curved blades on horseback, the warabite swords were quite short to be used while riding, which is quite puzzling. There was however a trend of increasing the length of the overall weapon, which might give some credit to the theory although the swords remained somewhat shorter compared to the straight swords used in the western areas.

Maturity, VII- X century

These types of swords, quite influential in the eastern regions started to spread and evolve in different designs and styles which will establish the direct link with later nihontō. In fact, it should be clarified that the development of later Japanese swords it's much more related to this native warabitetō and later designs rather than to the continental chokutō, and I will explain briefly this link later, although it's quite self evident.
Around the late 7th and 9th century, we start to see two main variations of these short swords. One of the least know sword is the so called ryukozukatō (立鼓柄刀).These blades, like the warabite swords were either straight or curved, and the latter extremely resemble the shape of the later Heain period uchigatana. Given the fact that the hilt was still curved, the sword is considered a wantō.

Examples of ryuukozukatō swords 

These swords are named like this because the hilt resemble the shape of a drum, and were usually short blades that didn't exceed the 60 cm. The hilt, like with the warabitetō was one piece with the blade, which are basically hira zukuri  with a broad width and elongated point. The hilt itself strongly tapers around the center.
Another important, despite minimal, development was the introuduction of a kenukigata (毛抜形) hilt style in warabitetō blades.

                                                  
                     Different hilts on warabitetō blades; notice the single piece construction.

Those blades are called kenuki-dōshi waribetō katana  (毛抜同士蕨手刀) and they feature rectangular openings in the hilts which resembled hair tweezer of the period. The reason for this opening is unknown: some scholars believe its purpose to have been shock absorption, while others contend that it served simply to reduce the overall weight of the weapon.

A kenuki-dōshi waribetō katana. Notice that the tip isn't rounded but it's just heavily corroded.

This is probably the most important link with the later period tachi developed in the 10th century which are considered the first true nihontō.
Slightly different but still very much related are kenukigatagatana which are identical to the former model with the exception of the pommel cap:

A close up ok this style of hitl; however, the weapon is a tachi and not a short uchigatana as the one descirbed above, but it still give you the idea of the main difference.

Again it is interesting to note that all these swords were one piece construction with the hilt and the blade and often had the tsuba integrated with the handle.
Moreover, given the short nature of the blade, these were intended as single hand weapons.
This is actually where the link is established, since the following development in the late 9th century was the kenukigata tachi which will be covered in a next article with swords of the late Heian period.
However, it is quite neat and straigthforward to see the linkage and development from the warabite, the introduction of the kenukigata hilt and later Heain period blades.

Sketch taken from  K.Friday that describe the relationship between warabite swords, kenukigata blades and later heian period tachi.

Finally, it is also suggested that curved warabitetō evolved and increase in length and were retained by the Emishi people who than migrated towards Hokkaido, giving birth to the Emishitō with the hilt construction being influenced by the works of the Yamato smiths, as we see that there is a nakago and the blade is supposed to be fitted with a wooden handle. These blades are even more similar to later periods katana and tachi.

A series of well preserved Emishitō.

The transition from the kenukigata blades and the 10th century early style of what we will associated with Japanese Tachi is rather complex, still debated and will be addressed in the future, as I want to dedicate more space to the typology and the details of warabite swords in this particular article.
Up to the 10th century, both chokuto and warabite swords as well as the other blades examined here were still produced and used. However, after the development of the newborn tachi sugata of the 11th century, said swords with the exceptions of the emishi ones, confined into Hokkaido, weren't produced anymore in Japan and were completely and slowly replaced during the late Heian period by the famous nihontō.

Typology & Steel
The warabitetō can be divided into 3 main styles (although I'm quite sure more sub categorization exist), and quite surprisingly, the least popular styles is what is used to represent the weapon as far as I could tell, namely the shortest straight blade with a kissaki moroha zukuri.

Type 1 sword

The first type which consist of 80% of the swords excavated and it was extremely popular in the north, namely in the Tohoku area and on Hokkaido, but some examples were also found in the Kanto and Chubu areas. Generally it's in hira-zukuri configuration and has long blade compared to the other styles, with a sori along the hilt and often also along the blade. 
Most tips tend to be a kamasu-kissaki. Wide blade and the tsuba is mounted from the tip and is held in place by the funbari (tapers from the base to the tip of the sword) of the base.

Type 2 blade

The second type is again in hira-zukuri and has short nagasa (blade length), but quite important, there is no sori on the blade, or actually we have a inverse uchizori like the ones found on chokuto of the same period.
 The sugata looks like an elongated triangle and because of that it is also called "willow shape".  The tsuba is mounted from the tip.These were discovered in the Kanto area, in the Chubu area down to the southern part of Fukushima Prefecture. Only three pieces were found in the Tohoku area. About 14,4 % of all warabite blades are of this style.

Type 3

The third type, arguably the most known one despite the low findings (4,5%!), is the one with the shortest blade length.
As I said before, they are in kissaki-moroha-zukuri, and are either hira-zukuri or kiriha-zukuri  Hira-zukuri blades are short, and both hilt and blade have no sori while Kiriha-zukuri blades are medium sized or long and narrow and show quite a strong sori along the hi.

Given the fact that the majority of these swords had a sori along the blade, despite some examples of being essentially straight, we still consider them curved swords.

Examples of warabite blades that could be categorized into the second style.

Finally, it might be interesting discuss some details of the steel used for these weapons.

Just like the contemporary chokutō, the blade was usually assembled with a laminated construction of piled pieces of different carbon content.
Most of them have a rather soft core inserted between layers of higher carbon content steel, other were made by more or less homogenous single billets of medium to soft carbon content.
Soft iron cores were essentially wrought iron in terms of carbon while the higer content was usually in between 0.2 and 03%.

These blades were usually hardened and they had an average hardness of  300HV to 350HV, in line with continental swords and lower compared to later period swords.
On the other hand, other part of the blades had the usually lower hardness value found on mild steel, around 150-180 HV.
Hence the steel can be classified as austenitic; however it is important to highlight that not every sword was hardened.

Speaking of hardening, the process was different from the ones used in later blade, and as a result yield different properties of the steel (a less harder edge, with less edge retention and more prone to rolling, but a more ductile blade overall) also due to the lower carbon content on the edge.

This process is described  in old documents by the term “uzumi-yaki“ , which means to fire an object by inserting it completely in hot ash.
This might suggest that with this additional measure, eventually the blades were heated by sinking them entirely in hot ashes of the cooled charcoal fire. However it might also to be the description of a rehardening at lower temperatures, around 400° C.
There are few blades which shows the classic clay tempering traces although it's hard to consolidate this hypothesis since the blade are quite old.


So for the warabitetō and early wantō swords that's all! I hope you enjoyed the reading and I highly suggest you to have a look at the aforementioned paper,aa, which is a much more detailed work on the subject.Please feel free to share and leave a comment below for any question.

Gunbai