On the Origins of Nihonto

7/30/2019 On the Origins of Nihonto

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On the Origins of NihonTo

An attempt of interpretation of NihonTo evolution

by Carlo Giuseppe Tacchini

Firstly published on JSSUS Newsletter Volume 41 n. 5October 2009

Updated and extended version
http://www.militaria.co.za/nmb/


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Acknowledgements

First acknowledgement must be given to Dr. W.W.Farris for his kind permission to use parts of hisworks and for the bibliography. Then to all the authors quoted in the sources list and the ones ,especially Masakuni, that with their works have enabled an armchair student to explain his ownopinion. I must mention Boris Markhasin for kindly providing material on Jokoto complex construc-tion and Dr. Moriyama Koichi for suggestions about the meaning of some difficult passages andwords. A special acknowledgement (and huge thanks) to Markus Sesko, which collaboration, in-formation, translations of a lot of material on early Japanese swords and swordsmithing havebeen invaluable to me. Last but not least John A. Stuart and Barry Hennick for proofreading myespecially poor English and Ken Goldstein, (Ph.D) for professional feedbacks and proofreading.

Disclaimer

All mistakes, misconceptions, misunderstandings or plagiarisms are surely mine and I take fullresponsibility of them. Just remember that this work is not intended for commercial purposes andstill remains simply an armchair students effort.I think to have been fair in using sources giving full credit to Authors and listing all pictures prove-nance on separate indexes but if anything in this work is not considered fair use for study rea-sons not related to commercial purposes and copyright infringement is a source of problems toanybody might be concerned, please contact me at [email protected] order to arrange the mat-ter.The same e-mail address will welcome any suggestion or input about this work-in-progress.

For the agreements taken with the sources I've been able to contact and the persons mentionedin acknowledgements, no part of this work can be used for commercial purposes. Any other useadmitted with credit to the original source, either me or the authors quoted in bibliographic notes.
mailto:[email protected]:[email protected]:[email protected]


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ON THE ORIGINS OF NIHONTO

By Carlo Giuseppe Tacchini

Form follows function - an old mantra for swords enthusiasts that has proved to be effective.To understand Japanese Sword youve to know Japanese History, by Fujishiro if I recallcorrectly. These two simple statements are at the heart of this article.

Introduction

Nihonto are today regarded by high-end scholars and collectors exclusively as artworks. In theiroriginal historical context they were weapons. World War II and the propaganda that followed al-most caused the extinction of the art of sword making.This resulted in many Nihonto texts lacking an exhaustive explanation of the genealogy and de-velopment if the Japanese sword as we know it. Its appearance is today regarded as a sudden,almost traumatic occurrence in the second half of the Heian Period, somewhere between 900

and 1100 C.E. (earliest dated fully-developed Nihonto being a Yukimasa dated 1159 C.E.)1. Thisblade has the three key characteristics of a Japanese blade - sori, yakiba and hada. Moderntachi entered the scenes of Japanese palaces and battlefields replacing the Chokuto of continen-tal design passing through Kogarasumaru and Kenukigata zukuri; but was this transition really sosimple? Curiosity and love for history made me wonder how such an advanced engineering asthe one we can find in modern tachi could have developed and evolved in ancient Japan. Thepoor results of a search of English texts led to a search of academic studies on ancient historyand Japanese texts on early Japanese weaponry. Cross referencing these sources led to thiswork. The fact that the establishment of the first fully developed Nihonto and the establishment ofthe Samurai class are placed in the very same timeframe suggests that there is a possible linkbetween the common explanation of Nihonto development and the old theory about the rise of theSamurai as a social class. This theory is called the Western Analogue Theory2.

Assuming that the European historical development was paradigmatic; Japan, after havingadopted the continental institutions with the Taih codes in 701 C.E., which compares to Romaninstitutions in the West, was forced by their failure into a period of anarchy by year 900 C.E. Thislasted to 1100 C.E. and resulted in the creation of private estates as entities of economic growthprotected by a new class of fighters, the Samurai. This compares with the rise of the EuropeanFeudal System. The establishment of the first Shogunate in 1185 was the crown of the process.Nowadays the whole historical process is regarded as a more evolutionary one, hence theEvolutionary Thesis has replaced the old one in many historical key passages.3 But, if the rise ofthe Samurai class has been revised from the one en vogue in the 60s, we cant say the samefor the theories about the development of Nihonto.Its not the task of this work to discuss the dif-ferences between Western Analogue and Evolutionary theories about the rise of the Samurai.In this article the Evolutionary Thesis will be applied to both Japanese history and the develop-ment of Nihonto. The aim will be to lead to the fixing of the final shape and the features of fullydeveloped Nihonto.

Requirements of a Nihonto

Although the term Nihonto is inclusive, in this article Nihonto will mean swords as defined as fullydeveloped when considering geography, artistry and technical aspects.

Geography- Provenance, meaning the sword has to be made wherever in Japan but not imported, even

when of continental design.

Artistry- Hada, that has to show patterns of layered steel- Yakiba, that has to be present as evidence of differential hardening - Hataraki- Sugata, that has to show a curvature.


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Technical- All the above- Shinogi, a ridge line - often inferring the presence of a functional yokote.- Shingane, the presence of a complex construction with different steels to improve shock re-

sistance

In the modern world of collectors, not all of the above requirements are needed to be present to-

gether in the same blade at the same time in order to consider it a Nihonto. Applying the samerequirements with a view to trying to explain the appearance of each feature that leads to our cur-rent view of Nihonto is the main goal.

Historical background from 300 B.C. to 701 C.E.The Sino-Korean influence and the introduction ofthe concept of

Counter-response and symmetry

Counter-response and symmetry is a term used to explain the process in which an antagonistreproduce the same kind of weapons and tactics used by the enemy he is fighting against or hehad experience of fighting with, because such weapons and tactics proved to be effective.4 The

development of weapons is strictly related to the development of strategies and technologies; soto follow the evolution of the sword linking military technologies and tactics to the people forwhom these were made is a must. Around 300 B.C.E. Japan entered (almost) simultaneouslyboth the Bronze and Iron Age. The Japanese soon adopted Counter Response and Symmetryreplicating continental bronze weapons. The smelting of the first iron arrowhead is fixed at the eveof Christian Era5 and by the end of 1st century C.E. blacksmiths, either native or immigrated, wereproducing iron swords in Japan6. Significantly, the same date is given for the first archeologicalevidence of war victims found at Doigahama, Honshu.7 The arrival of farming created differencesamongst populations and poorer begun to attack neighbors for food and war spread all over thecountry . It soon was evident that the supply of iron was a problem. Indigenous production was

too low in Japan untill the late Kofun with the introduction of the Tatara. Supply of raw materialshas been suggested as the main reason for the Japanese becoming involved in politics on theKorea peninsula in the 4th century8. The Japanese military had significant inputs from wars be-tween Yamato-Wa, Silla, Paeckche and Kogry. These inputs came either from expertise of im-migrants (especially with a first great flow of immigrants after the destruction of Kaya States in562) or from direct experience of fighting on the peninsula.Amongst them, the most important was surely the use ofhorses for fighting. Back then horses were expensive and oflittle use other than for war. Therefore civilized societies thatused the horse extensively tended to have specialized fight-

ers9

, usually wealthy enough to provide them with such acostly weapon. Secondly the lightly armored mounted archerwho used both bow and sword became the Bushi. Notablythe stirrup evolved in the 6th century.10 According to the Ko-jiki, a Korean blacksmith named Takuso was brought to theimperial court from Paeckche during the reign of EmperorOjin. There are no firm dates for his reign, but he is the old-est of the emperors in those chronicles whose existence isaccepted as having been real and a dating to late 4 th centuryC.E. and might be an acceptable hypothesis. The Kojikialsotells of an exceptionally talented blacksmith from Silla whowas employed by the court in the 12th year of the reign ofEmperor Bidatsu (583 C.E.). It was he who provided instruc-tion in the techniques of smithing.

Fig. 1


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In these early periods (300-500 C.E.) the ceremonial swords were, generally, either straight anddouble edged, much like the well known Ken that resembled the ones of the Late Chou Dy-nasty, or snake-like Meandering Swords (Dak-ken). Early examples have a ring-pomelledtang. This ring later moved to the mounting as one of the fittings. The cover of the catalogue bythe Suwa City Museum11 shows all three of these blades/features. Note that these three are notto scale.Many swords have been excavated throughout Japan, starting from Kyushu, and manyfrom what the ancient sources call the Eastern provinces. The term Eastern Provinces backthen meant the Kanto plain and northeastern Honshu, well-suited for horse breeding. The storyof Prince Yamashiro and his rebellion to the Court tell us that most of the royal retainers(Toneri) originated and were hailed from that area12. Kanto already had a strong military andeconomic base, and its importance was rising at the eyes of the Court after the fall of the Ko-rean allied Kaya States in 562 C.E. 13 There is no consensus on how much the Court powerwas effective here at this stage of Japans history or about the ethnicity of Emishi (see appen-dix 1). It is suggested that the Kanto could have been a politically independent region. It wasfairly advanced in both weapons and fighters for the periods standard. TheKanto was not nec-

essarily subju-

gated by the Ya-mato Court butrather served itas a vassal.14

Most scholarsagree that theKanto alreadyhad his own welldefined identity,as suggested by

the use of spe-cific geographi-cal terms likeEastern Prov-inces or Azuma (TheEast), and alsohad a specialmilitary impor-

tance by year 600 C.E. A sword dated to this period and similar to the one in fig. 2 bears ex-

tremely important inscriptions showing Chinese characters used to write at least a few Japa-nese words. This linguistic evidence is still highly debated and need further studies. This bladeis identical to continental specimen and might be an imported one with inscriptions added later.Another possibility is that a Korean immigrant might have made this sword as Korean linguisticelements are also found in the same inscription15. The Sui (589-617) and Tang (618-907) Dy-nasties had an aggressive politic that lead not only to the unification of China but also to a pres-sure against the Korean States, invading them in the 630s. Japanese were aware of what washappening as they still had strong interests and ties with Korea. Surely they wondered about theintention of Chinese armies to invade Japan. It is now believed that the anti-Soga conspiracyand assassination of 645, known as Isshi incident, was aimed to give to Japan a new ruler ableto catalyze the consensus needed by the hard times16. Prince Naka who focused on militaryaffairs was that ruler. Kanto and Mutsu were divided into 8 regions. Soryo (governors) were sentto strengthen the Courts control17 and to rule the regions. These governors were recognized bylawgivers as a distinct entity18. Armor and swords were collected into government ruled arse-nals.

Map 1


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Fig.2 From Funayama Tumulus, Nagomi Machi, Kumamoto, Kofun period, 5 th/ 6th century, NationalTreasure, Tokyo National Museum

No one was allowed to own them unless directly involved in the defense against the Emishi,eastern barbarians or disobeying people. The new Emperor promulgated the Taika ReformEdict, a keystone event in Japanese history .The authenticity of the Edict is now debated buttwo provisions of Articles 1 and 4 are considered legitimate and related to this work 19 .

(Article 1) Let Border Guards be provided

(Article 2) As to weapons, each person shall contribute a sword, armor, bow and arrows, a flagand a drum20

The Border Guards were provided by Eastern Honshu to protect the supposed target of a Chi-nese invasion, Northern Kyushu. Flags and drums are implements intended to coordinatetroops movements in what were continental tactics of mass peasants infantry armies that, evi-dently, started to be used together with the mounted archers. In 645 in order to reinforce theCourts control on eastern Provinces, growing fast in military importance, orders of collectingprivate weapons in such Provinces were issued21. On the continent things went from bad toworst and the Tang armies, after having attacked Kogry proceeded against Paeckche. Silla

entered the war too, on the Tangs side22.Now Japans Court had to take steps in the attempt tostop the tide away from their shores and sent 3 expeditions in aid to Paeckche from 661 to 663A.D., using a traditional approach, so fighting technology and tactics were the traditional ones,not following the continental example, yet, even after two decades from the attempt to introducecontinental institutions. Soldiers for the expeditions were mainly hired from Kyushu and WesternHonshu23 . After an initial draw on the battlefield the Tang fighting tactics proved to be deci-sively effective at the final battle of Paekchn River, that according to Korean and Chinesesources cost the Japanese thousands of men and horses24 and is still regarded as one of theworst defeat in Japanese history. Disunity and fighting tactics based on individual skill andproud were no match for the more numerous, better armed and better drilled Tang armies , well

coordinated by capable generals using formations of infantry en-masse. 668 A.D. found all ofKorea under hostile control, meaning the end of one hundred years old Japanese foreign policy,relying on continental relations with Paeckche against Silla.


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The Court was moved to mi on Lake Biwa, to stay at a distance considered safe enough fromcontinental invasions. The usual sea trade routes were now no more reliable and the iron supplyfrom Korea was harder to get in order to increase the internal production. Import of swords wasaffected too. This possibly forced the Japanese to enhance their iron production and smithingtechnical skill thru the help of immigrants. The events on the peninsula created a flow of Koreanrefugees with artisans, engineers and people with any kind of knowledge and skill to enter Ja-

pan and the capacities of these men had to be of high quality if they were allowed to contributeto fortify Kyushu (Farris suggests these fortifications were the basis for later Dazaifu) and all theway thru mi with Korean-style fortifications against the supposed ongoing invasion from Tangand Silla allied forces. Board Guards garrisoned Tsushima and Iki islands. Again, counter-response and symmetry took place, with the need of further changes in the military organizationthru the first general census in 670 A.D. A reliable census is a must in order to organize a con-script army as the one that was in the projects of the Court 25. The Paekchn River defeat hadalso political consequences. In the struggle for replacing Tenji, that was no more in augeamongst the vital military lite of local strongmen (Kuni no Miyatsuko), Prince ama was able todefeat Prince tomo for having denied him access to the military resources of Eastern Prov-

inces through the blockade of Suzuka (Ise) and Fuwa (Mino) passes and being able to raisemounted troops in these Provinces rich in weapons and soldiers26. Prince tomo too benefited,at Kurafu battle, from the valor of a contingent of mounted troops that had immigrated from theEastern Provinces27 , a further evidence of the military importance of the Kanto as a source ofskilled mounted fighters. In 673, Prince ama became Emperor Temmu, the Emperor thatstarted to ferry Border Guards from the Eastern Provinces to Northern Kyushu on a regular ba-sis28. Later, to improve and enhance the military value of Kanto the Court sent specialists onChinese tactics based on Sun-Tsus The Art of War and other classics29 and established gov-ernment-controlled pastures for military horse supply30.

The Japanese sword in early stages: IVth

-VIIIth

centuryShinogi, Hada, Shingane and Yakiba enters Yamato.

In Japan from IVth to VIIIth century C.E. there were the same types of swords we can find inChina from the Jin to the Tang Dynasty (265-907 A.D.). The trade/cultural/diplomatic relationsbetween the two countries were both direct and indirect thru the Korean states. Early swordsintroduced when Japan entered bronze/iron age are of models already established and evolvedon the continent, where the ridged types were gaining an increasing popularity. Differences

soon begun evident in the mountings rather than in the blades, that needed little to no changesas they fit well the purposes of actual combat tactics either still too primitive or (after the battleof Paekchn River) mirroring the Chinese model of maneuvering mass infantry. The use ofmounted archers, even if quite common, hasnt affected the sword shape yet, as seems thestraight, single edged model fulfilled well enough the needs.


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Early swords typologies

Fig. 3 Different lengths and tangs for each type have been found. In black the cross-section of each part.

__________________________ 30 cm / 11,81 in


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In Japan the length of found specimens vary, the longer being even more than 1 meter and theshorter around 60 cm. Anyway the majority are in the range of 60s-70s cm, length that shouldput them into the category of utilitarian weapons rather than court or ceremonial ones, as mostlikely the difference between the two types might have been in the mounting rather than in thelength. Dak-ken, the meandering sword as far as I know is found only in Japan and is purelyceremonial. Picture n. 3 shows the models used in this span of years, evolution being from topto bottom, even if possibly not entirely correct, either in chronology and surely in proportions, asdifferent models, with different lengths for each model, co-existed in the same periods for sometime. First thing that attract our attention is the progressive appearance of a ridge. Smithingtechnologies increased thanks also to the flow of immigrants not only from Korea but also fromChina due to the political situation after the collapse of Eastern Jin dynasty, during the Northernand Southern Dynasties, a period of both problems and notable technological advances as thestirrup. The Shinogi (ridge) first appeared in China at least during the Han dynasty and enteredJapan as soon as the trade allowed it. Shinogi (ridge)is a natural addition to the flat (Hirazukuri)blades in order to obtain a more performing sword and is mainly intended for long and mediumblades.It firstly appeared in Kirihazukuri blades, the same as in fig.4. These blades has the ad-vantage in having a thicker and consequently heavier and more resistant body maintaining a

thin, hence sharp, edge thru the application of an angle. The

result is a 5 sided cross section. This is a very good en-hancement for swords that might strike hard objects as ar-mor or bones. A thinner triangular section (Hirazukuri) issharper but also more prone to break due to the shocksmentioned. More, the beefier upper section of Kirihazukurigives more weight to the kinetic action, and this possiblyremedied to the lesser cutting ability. With time swordsmithsrealized that to move up the Shinogi would mean to addsharpness to the edge, in some way mixing the Kirihazukuri

(upper part of the blade, above the Shinogi) and Hirazukuri (lower part of the blade, below theShinogi) maintaining a five sides cross section. This proved to be the more effective cross sec-tion for long blades in Japanese history, with a perfect mix of resistance, weight placement and

cutting ability. In this work I cant discuss the Niku (meat, a curvature in the angled section thatimproves cutting ability and edge resistance to wrongly angled cuts) because of lack of materialin reference to pre-Heian swords. Image shows at left (A) Kirihazukuri cross section, at center(B) Shinogizukuri and at right (C) Hirazukuri cross section.

Hadaand ShinganeHada (texture) is the result of folding and hammering (Tanren) the steel bar during the forgingprocess (see fig.4). This ancient practice has been developed in China where was present atleast from the early Han Dynasty (IInd century b.C.). It serves primarily the purpose of refiningthe steel from impurities that gets pushed out from the heated bar by the repeated folding andhammering actions. The practice has been imported via the already mentioned ways and laterevolved and has been developed to the point that it allowed the smiths to be able to achieve

many different types of textures that appear in different parts of the blade according to the waythe steels were folded and how the blade was assembled. These textures, often mixed in differ-ent compositions, are often specific features of a given school and a precise Kantei(appreciation) point. Shingane (Inner steel) is a term used when the blade has a complex con-struction, implying usually at least two different bars of steel. Ill give a better explanation later,but for practical reasons Ill not split the discussion into two different chapters for Hada andcomplex construction/engineering of the blade.

Fig. 4 Han Dynasty ring-pommelled sword found inDuan River (China) andpolished by Prof. Min Yan,showing early type of Hada.

A proto-shinogi and proto-yokote, forward-angled , arealso present.


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Chinese swords that were made of folded steel were referred as Thirtyfold, Fiftyfold,Eightyfold, Hundredfold refined steel, and according to D.B. Wagner the swords unearthedin Eta-Funayama (Eightyfold Refined, Vth c. C.E.) and the one unearthed in Sakitama-Inariyama (Hundredfold Refined, 471 or possibly 531 A.D.) have been forged in Japan31 .Wagner gives also a very interesting explanation of the meaning of Thirtyfold and Fiftyfolddiscussing the cross-section of two Chinese blades of the Ist century C.E. that show definite lay-ering in the microstructure. The sectioned blades show that they are composed of three re-gions : a central section of about 2mm of thickness and two mirrored side sections of about1,5 mm thickness. The side sections are made of alternate layers of respectively 0,4 and 0,6 %carbon content while the central region is uniformly of 0,7/0,8% carbon content 32. Wagner re-ports a very interesting hypothesis on how the number of layers were inscribed on the bladedue to the rules of quality control adopted in China (and possibly in Japan too ifwe acceptWagners opinion about Inariyama and Funayama swords as forged in Japan, even if not nec-essarily by japanese smiths), has a practical explanation after the microstructure analysis. Theinscription might state in an approximate (but very close) way the number of layers rather thanfolds (interestingly, to Nihonto enthusiasts the misuse of the term fold instead of layer is notnew). Using the Fiftyfold refined steel sword example with a Sanmai (three sections) lamina-tion method we may infer the following sequence :

- A bar of high-carbon steel (0,7/08 %) is folded 4 times giving 16 layers. This is the edgehard steel.

- One bar of low-carbon steel (0,4%) and one bar of medium-carbon (0,6% ) steel arewelded together .

- The resulting bar is further hammered and folded three times, giving a final 16 layers. Thisis the softer steel that will be either the jacket or the core of the blade according on howwill be performed the next passage.

- The softer bar is wrapped around the harder one. The sword will be made hammering theresulting bar and as the wrapping will leave the harder edges (the blade in question is adouble-edged jian) outside well obtain a 16 (left side) + 16 (core) + 16 (right side) total-ing 48 layers. Very close to the figure of Fiftyfold. Following the same procedure we

can infer that Thirtyfold should be 8+8 (soft) + 16 (hard) = 32. Eightyfold 8+8 (soft) +64 (hard) = 80. Hundredfold 16+16 (soft) + 64 (hard) = 9633.

Fig. 5 Left : Picture of the actual blade,Top right, high-res picture of the layers,bottom right Wagners rendition of theabove discussed Jian (two-edgedswords) cross section of the layers.

Another interesting example ofcomplex construction has beenfound in Korea. A chisel exca-

vated in southern Korea datedfrom the third century B.C. tomaximum the third century A.D.has pure iron at its centre andan outer layer of steel with0.81% carbon and 6.31% sili-con. This silicon content is sur-prising; modern iron rarely hasover 2% silicon, and one gener-ally finds even less in ancient

iron. It is suggested that thischisel was carburized by dippingit into molten cast iron.34


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Even if this per s doesnt enforce the theory of early use of shingane in swords, it tells us thatthe idea of a complex construction to absorb shocks was considered useful not only for militarypurposes, supporting the theory that this idea is older than supposed.Returning to Japan, however, Dr. Honma Junji, in discussing the swords preserved in the Shs-in states :seem however that they, unlike later swords, do not have the Shingane (core steel) added

inside. They were probably made by hammering the Kawagane (skin steel) flat and folding itlengthwise, with the edges meeting at the mune (back) for cross sections (sectioned parts) ofswords unhearted from proto-historic tombs (Kofun) frequently show such construction. 35and that likely Shingane as functional engineering of the sword firstly appeared in Nara or earlyHeian period. I can understand this statement but I believe its not entirely correct as there weremany different types of complex constructions and to discard the others in favor of the suppos-edly more common may result in losing interesting options. At this regard it would help a scien-tific and systematic study of sectioned Jokoto from different periods and excavated from differ-ent locations. Sadly, the available material seems to be scarce, likely due to the destructive na-ture of the needed metallographic examinations. So far Ive been able to find only the studies ofSuenaga Masao that sectioned a few Jokoto swords from archeological sites and the studies ofMasakuni Ishii on WarabiteTo and both are accurate but not recent. As this is a delicate and

quiet complicate matter, a better explanation of the terms Kawagane, Shingane and Hagane isneeded :

- Kawagane means Skin steel - Outer steel- Shingane means Core steel - Inner steel- Hagane means Edge Steel - Steel which the Ha is made of

Hagane has a unique meaning that cant be misunderstood and is rarely used, but a Japanesefriend whom I rely on, with his usual kindness explained to me (confirming my opinion) thatShingane and Kawaganeare not strictly technical or legal terms. Therefore, they do not always have unique concrete

definitions as you might expect. Even among japanese native speakers, there may be different

opinions. The meanings of Kawagane and Shingane as skin iron and core iron respec-

tively are general interpretations. Especially, shingane is a term used not only for Nihonto. So,

the terms are not automatically connected with the characteristics of the materials used for the

blades. However, when we talk about Nihonto, we tacitly assume that Kawagane is high carbon

quality steel and Shingane is inferior soft steel. This is a tacitly understanding which is valid only

among Nihonto community. That understanding is natural for us, but when you talk about the

unique construction of ancient blades, it might be better to clarify the usage of different materi-

als explicitly to avoid unnecessary confusion.36 This specification was needed for the sake ofthis work as early swords shows types of complex construction that might look strange to nowa-days NihonTo collectors but that makes perfect sense in such an early period in which Korean

and Chinese influences were very strong. Kawagane and Shingane, in fact, commonly refer tothe two types of steel we find in Kobuse, the present-day most known and common laminationmethod. In the common understanding of this type of construction the Kawagane is higher qual-ity steel with an adequate carbon content and carefully manufactured while the Shingane is asteel of scarce quality to which isnt given a special attention in manufacturing. Not to mentionthat this understanding might be not entirely appropriate even for nowadays NihonTo apprecia-tion, Ill try to demonstrate that this doesnt apply to ancient swords. In fact, as we have seenwith the Jian shown in Fig. 5, in China and consequently in Korea and Japan that the Sanmaiwas used also in a reverse way, in which the harder steel was placed between two layers ofsofter steel. So, in this case, the terms Kawagane and Shingane maintains their meaning only if

we have no preconceptions about the material they are made of. . More, well see there existsalso horizontally assembled forging methods, in which the soft steel layers are placedoverthe harder steel ones.


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So here which one is Kawagane and which one is Shingane ? It Is also possible to make bladesby inserting the harder steel into the softer one. This is called Warihatetsu in Japanese. Here-under Sanmai and Warihatetsu in present-day made Hocho, kitchen knives, that resemble

some of the early types of laminated construction, with the harder steelplaced in between (left) or inserted into (right) two plates of softer one as inthe picture at left. Having in mind that its extremely difficult if not impossibleto judge the type of construction a sword is made of without sectioning it, Ican now beg to disagree with Dr. Honma Junji about the absense of com-plex construction in such early swords. I think that his statement referres toa sword with a specific type of construction with four layers (called by Ma-

sakuni with the uncommon an quite odd term , Shikakudan-to)

which is supposed to have been produced by hammering a single plate ofsteel flat and folding it lengthwise two times, with the edges meeting at the

Mune of the blade. This results in a cross section with 4 layers with no real Kawagane nor Shin-gane. However it might be there was more than one way to produce a cross section of 4 layers.Suenaga states that there are complex constructions that result in 2,3,4,5 and 6 layers, assem-bled either vertically or horizontally. The explanation of folding twice the same steel bar worksfor 2 and 4 vertical layers only and even for these there might be other explanations that includethe use of different steels as well. Ill try my best to depict all the possible variables starting fromthe already mentioned studies and to link them to later more complex constructions in a sort ofgenealogical tree.Here Suenaga suggests that 4 layers swords can be made also lining-up 4different bars of steel :

it seems that the depicted blade is forged of four vertically lined-up pieces of steel.37

There is also another possibility that in my opinion could explain better the presence of 4 layersin the mune. The blade is made hammering flat two lined-up bars of steel of different carboncontent and then a single fold lengthwise is performed. This would avoid having a weld in theHa, with possible detrimental effects on the reliability of the blade (see figure B in the tableInterpretation of early complex constructions). In a similar way, using a single bar hammeredflat and folded only once we can explain a two-layers complex construction that appears in theMune of some blades, with no detrimental results on its resistance to shocks (Figure A in theabove mentioned table). Also the Shikakudan type described by Dr. Honma Junji produces fourlayers with two folds instead of one but this solution wouldnt work for examples in which isshowed an harder Kawagane. For these we need to hammer flat two bars of steel with differenthardness and fold them lengthwise leaving the softer one in the inner part of the fold. Suenagassuggestion for blades that shows three layers in the Mune and harder Kawagane is, in my opin-

ion, better explaned by the process showed in figure D, again to avoid placing a weld in the Ha.Of course these are just interpretations and I cant support them with first-hand researches onactual blades. It is more then possible that Suenaga had his reasons to state what he had pub-lished and possibly Im not aware of important details about the matter. As regards the diffusionof the different methods Suenaga writes :

The vast majority of the higher-quality blades show a vertical forging-method. Vertical and hori-

zontal forging methods (i.e. the way the layers are arranged) are in a proportion of about 70 to30, but no intermediate or compromise forging methods are found. Most specimen consist of

three to five layers, and combinations of two or six layers of steel are rather rare. From this point

of view we can say that in most cases ancient sword blades consist of three layers of steel

forged in a vertical manner, so to speak a shingane with each one layer of Kawagane to thesides. And the incorporation of horizontally arranged layers too flowed eventually into the well-

known forging methods of the Japanese sword. Therefore it is important for the understanding

of the history of development of the Japanese sword to look back on the forging methods of an-

cient blades.38


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Entering in better details Suenaga explain the sectioning of Kofun Chokuto in vertically and hori-zontally assembled method :

Elaborate blade with a vertically assembled forging method(Hirazukuri Chokuto)

excavated: Kofun near the city of Isezaki, Gunma district, Kzuke province affiliated with:

Science department of the Imperial University KytoThe example shown in picture (6) (plate 41) is divided-up into four cross-sections, shown via

pictures (5) to (9) (see Fig.6). When looking at those cross-sections, one can see that the blade

consists of a Shingane inserted between two layers of Kawagane, and further that the vertical

assembly of these layers is very consistently forged along the entire length of the blade.

Further, there are relative few slag inclusions, which makes this piece a masterly work very

carefully forged for an ancient blade. And it can also be grasped that it were such swords which

layed the foundations or set the course towards the later forging methods of the fully developed

Japanese sword. One can see on the basis of each of the cross-sections synthetical depiction

that the Shingane consists of ferrite, and the Kawagane parts of sorbite. Moreover, these com-

pounds are very fine, and this is the result of a considerable high-temperature forging, namelythe blade had to be exposed to a temperature of about 850C for a longer period of time. Pro-

bably the blade was hardened at a temperaturte

close to 850C, and was then annealed (yaki-

modoshi) at about 500C. A difficult task within

this forging process is to select the proper steel

fragments for each layer. The about 20 mm long

white ghost-line in one of the cross-sections

shows us that there is a difference in carbon

content of about 0,3% to the surrounding layers.

Well, the practical efficiency of a sword dependson the attention payed to the rough forging, the

forging together of the layers, the heat treatment

and so on, and this blade is from the point of

view of forging technology and skill an excellent

piece.39

Elaborate blade with a horizontal assembled forging method(Hirazukuri Chokuto)

excavated: Kofun near the city of Fujioka, Gunma district, Kzuke province

The example shown in picture (11) (plate 42) whose mune is also hardened (still is a single

edged sword) is divided-up into five cross-sections. Pictures (1) to (5) (See Fig.8) show the syn-thetical depictions. Because at a horizontal assembly of the steel layers it is important to show

the horizontal and vertical course, two cross-sections and synthetical depictions were provided

for each examined section. Well, the corresponding sections between cutting edge and mune

were polished just as much as to get a perpendicular and representative cross-section. Looking

at the cutting-edge area of the synthetical depiction of the kissaki area (1), we see that it con-

consists of six layers of horizontally assembled steel layers.What we can assume is that the

uppermost layer consists of a mix of martensite and troostite, layer two contains especiallymuch martensite, and layer three consists of ferrite mixed with fine-grained martensite.

Fig.6


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Between layer three and four, a white ghost-line occurs. Layer four consists of a mix of mar-

tensite and ferrite, layer five of martensite, troostite, ferrite, and other structures, and layer six

nearly almost of martensite.The cross-section for the horizontal layers shows that the mune area of the blade contains

not only martensite, but is actually a mix of martensite, troostite, sorbite, and ferrite. At a closer

inspection of the cross-section, one can see that the martensite content is gradually decreasing

the farther from the cutting edge, and further that the cutting edge itself consists of nearly all

martensite and is therefore able to maintain a certain sharpness. OMISSIS In brief words,

the upper and lower regions of the horizontal view of the cross-sections can be identified as

martensite structures. OMISSISThe gap in the cross-section (5) is the mekugi-ana

(interestingly here it was sectioned also a part of the nakago). The carbon content is about

evenly distributed over the entire blade. Well, because of the rather low carbon content of this

sword, the cutting-edge and the mune section were treated with yakite, and especially towards

the kissaki, the hardness and so the sharpness increases. This we have seen via the high

and increasing martensite structures towards the kissaki area. We should not overlook the fact

that the cutting-edge was contrary to this so to speak as countermeasure against fragility

once more treated with a high amount of yaki-modoshi. It was this sense of regulation within the

craft of sword forging which leventually led step by step eventually to the development of the

Japanese sword.40

There are two interesting things we have to consider when talking about ancient laminatedmethods. The first Is that many of the swords in the time were considering were made of im-ported iron, in the form of small bars often from different original sources, or mixed with indige-nous (depending on timeframe) or recycled metal. It can be supposed that some of these

swords have an uneven distribution of the carbon content due to the different amount of carbonpresent in the several bars used to hammer out the starting bar(s) that were combined together.So the choice of the starting material was, already back then, a very important process, but sub-ject to availability of the rough material. Steel with an homogeneous and correct carbon content

was possibly a problem, and the quantity of impurities too. Identical workout on small bars withdifferent carbon contents gives the result of zones with different carbon contents in the final bar/s that will form the finished blade. This is evidenced in the studies of Suenaga, in which unevendistribution of carbon content, presence of slag even of important dimensions and bad weldingoften appears in the sectioned blades. From the above description we see that Suenaga stud-ied also the section of the Nakago with the Mekugiana. Ive been lucky enough to have a col-laborative friend with the same interest in ancient japanese weaponry that provided me with apicture of the broken Nakago of a Late Kofun Jokoto in his collection. . Its preserved in the Ha-baki/Fuchi of the original mounting and it possibly gives us much interesting information, or atleast material for suppositions. In my opinion it shows a Sanmai construction, with implicationson the forging process.

Fig. 7


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In this ancient Nakago we can clearly see different bars welded together. But is seems to tellmore. Notwithstanding its slightly angled it looks like it was built not by three vertically lined upbars as Suenaga seems to suggests about the one (Fig.6) discussed before, but by two, theKawagane one folded wrapping the Shingane, very much like todays ones. The thickness ofthe three layers looks appropriate and balanced, the shape of the Shingane bar still has a veryregular appearance notwithstanding the centuries and strong oxidization. An uneven distribution

of Shingane is a concern in traditionally forged blades with complex construction and often amatter of discussion about the effectiveness of some of these methods. It seems to me this isntthe case.

Fig. 08 Laminated late Kofun period chokuto. Lookinginto the remnant of the tang preserved into the habaki-fuchi. At right layers boundaries highlighted, yellow isouter board of Kawagane, red is outer board of Shingane.Boris Markhasin collection.

I stated before that there is no absolutely safeway to tell if an healthy blade has complex con-struction without sectioning it, but technologymakes available tools that might help us, stillmaintaining the needed prudence.

The following is an image of part of the Mune and all the Nakago of a long straight Tachi and that

is dating to ca. 600 AD. Nagasa is 85.5 cm with a 17 cm tsuka, and a 1cm Kasane (Fig 09). Aradiograph has been taken with a commercial technology called Gamma Radiography (Sr 92source) used to detect structural defects in metals. The result of the radiograph has been ad-justed in saturation to obtain the picture hereunder. It possibly shows lamination in several areasof the Nakago and could suggest 2 differing steel compositions in the blade and into the upperNakago.The saturation gaining of the image to attain the supposed differentiation of two metalshas resulted in the loss at the outside border. Consequently, what might be Kawagane has beenreduced in thickness by 30% in all the blade and Nakago length. However, if the suppositions areright, then the Shingane is thicker in any case. This is possibly explained by the use of the form ofcomplex construction depicted in fig.10 plate D and by loss of material due to oxidization.TwoMekugiana are shown and what seem two weak areas as well. It looks like there is a repair witha differently built bar. The sword is very long and the Nakago is hidden by Tsuka remains, somine is a shot in the dark with blinded eyes, but in the course of narrowing, it looks like whatcould be the Shingane is lost about 40% along the tang: The rest might be only Kawagane, sug-gesting this sword was built inserting the Shingane only from half the Nakago onward. Thismatches with what suggested by the previous image of the cross section of a tang dated aroundto the same period.

Fig. 09Long straight Tachi , around 600 A.D., Markhasin collection.


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The last section which appears thicker and healthier, starting just after the second weak point, lookslike the result of a mending or compositing a new section of metal. There is also a delamination just abovethe second Mekugiana what might be an inserted repair point.The sword is still under examination and fu-ture results will possibly give more information. It seems that Dr. Honma Junji and Suenaga Masao dis-agree on how some construction methods were obtained but it might be a matter of interpretation. So Illnow discuss about how the 2, 3, 4 and 5 layers swords might have been constructed. Well refer to the fig-ure 10. Images A B C and D are rendered according to Dr. Honmas opinion of a single bar of steel ham-

mered flat and folded lengthwise, either once or twice, while at left there is the literal interpretation of Sue-nagas lined-up construction. We have to consider the construction types under the point of view of reli-ability. The difference is easily spotted in the most important part of the sword : the edge. Building theswords with a lined-up construction would mean having the weld/s between bars both in the Mune and inthe Ha. This means that the Ha could be subject to catastrophic failures if the welds are not very well made.In one-fold/one bar and one-fold/two bars (Shikakudan) constructions the weld/s occurs in the Muneonly, a part of the blade much less subject to stresses then the edge. Basically, its a safer and more ro-bust way to produce a sword that shows the same number of layers in the cross section. If we apply this

reasoning to the 3 layersconstruction too, somethingdoesnt work. An alternativeway to obtain a 3 layers verti-cal construction without a

weld in the edge is to useonly 2 bars of steel. The firstone folded to wrap the sec-ond. This might be an evolu-tion of the one-fold/one barconstruction, but seems sucha construction was already inuse in China in ancient times.The difference between thisone and the Sanmai is that inthis one the harder steel ,when present, has tobe placed to form the outer

layers, while in the Sanmaithe hard steel is placed in-side. As the blade discussedby Suenaga shows theharder steel used as Kawa-gane, then the one-fold/twobars construction seems thebetter solution. The samewould work for a four layersconstruction as well. Ham-mering flat two bars of steel,welding them one upon theother and then performing a

single fold lengthwise wewould have a section as inpicture H. For sake of sim-plicity Ill use two tem-plates that resemble thesection of a present-dayHirazukuri for Jokoto andShinogizukuri for NihonTo,highlighting with differentshades of grey the differ-ent steels, the lighter thegrey the harder the steel.

Fig. 10


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Fig. 11


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Now, I would like to quote Honma Junji from NihonTo Koza (in the translation of Mr. H.Watson)when discussing Ko-Bizen swords made in the very early periods of the fully developed Ni-honTo (second half of Xth century) :Jitetsu: As for the works of this jidai, there are a great many which seem to be close to mukukitae (also called Maru , made of one kind of steel), and even with those that have been pol-ished down quite a bit, there are very few in which the shingane comes out of the ji and be-comes rough. 41

Dr. Honma Junji previously appreciated the Jokoto in the Shsin as without Shingane and pos-sibly made in the two-folds/one bar (Shikakudan) construction. His opinion is highly regarded,with good reasons, and we must consider it very seriously.So, at least a few KoBizen blades show Shingane. However I cant get more precise detailsabout the over polished swords mentioned. Considering that complex construction either piling-up or welding side-by-side plates of steel was already in wide use by far and that Shingane is aterm used when talking about and in the context of the blade construction but not implying anytype of quality of the material (i.e. in a Honsanmai construction the inner steel is the harderone) , I can try to give possible explanations for the rarity of KoBizen swords showing roughShingane :

- The KoBizen swords showing no Shingane are skillfully made in the old one-fold/onebar or two-folds/one bar (Shikakudan) way, a single bar of steel folded once or twice,lengthwise. Being the steel the same for every layer its hard to distinguish between lay-ers even if heavily polished. Not so for the ones made in (Hon)Sanmai or Makuri inwhich the difference between steels can be more evident.

- Muku / Maru Kitae has always been used, together with other types of construction, orwas (re?)introduced in long swords smithing too, using only top quality steel, now nolonger imported because availability from indigenous bloomeries, maintaining the pro-duction of a smaller amount of swords with Shingane, again with the same high qualityKawagane. The latter eventually proved to perform better dooming to oblivion the Muku /

Maru construction for long blades in a relatively brief time.

- All the swords have Shingane but the steel used as Shingane in such early swords is ofa quality as high as the Kawagane. Both steels had an equally accurate Tanren. Thedifference is only in the ability of the two steels to react to the hardening process reach-ing different hardness, e.g. they differ in the carbon content only. This would mean thatno difference in quality (both well-refined) nor in pattern (folded the same way and withthe same care) is discernable. Hence a great difficulty in discerning the two, making thebecoming rough (ruining the appreciation of the piece) a rare occurrence.

- The ones with rough Shingane were the majority but most got discarded and replacedlong ago while the less numerous ones in one-piece construction survived more easily

(under this point of view a sword with complex construction has a shorter life in real pro-longed warfare situations). The over polished survivors being the best/most reveredones or simply the ones that got over polished late enough.

- The Shingane in (some of?) the healthy ones is thin and not revealed yet.

- A combination of some or all of the above.

Now lets discuss the hada and the activities due to the use of differential hardening in earlyswords compared to later ones. Weve already seen how the technique of folding the steel dur-ing the smithing has reached the archipelago with Korean immigrants and that it was in use in

China for centuries. Now we should look at similarities in the ancient works and the workman-ship found in later, fully developed NihonTo. To do this, weve to use the better preserved an-cient swords available, as to say the ones treasured in the Shs-in Depository.


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Dr. Honma Junji describes them this way :Kiri-ha-zukuri are the most popular type and there are swords in shinogi-zukuri that look like kiriha-zukuri at a glance, also many kissaki-moro-ha-zukuri (mostly kiri-ha-zukuri) are seenamongst them. There are also some swords in Kogarasu-zukuri. Shallow sori is recognized inthem, their mi-haba is wider than that of the Japanese sword in general, most swords havemaru-mune, jigane looks soft, nagare-hada is common and masame-hada is also seen, and

hoso-sugu-ha is popular and skillfully tempered. Boshi is sugu or gentle then turns back in ko-maru with short kaeri and is elegantly tempered with tight a nioi-guchi. The jigane is coveredwith thick ji-nie, sunagashi and hakikake are seen, and the hamon starts with yaki-otoshi.42

Kiri-ha-zukuri are the most popular type and there are swords in shinogi-zukuri that look likekiriha-zukuri at a glance, also many kissaki-moro-ha-zukuri (mostly kiri-ha-zukuri) are seenamongst them. There are also some swords in Kogarasu-zukuri. Shallow sori is recognised inthem, their mi-haba is wider than that of the Japanese sword in general, most swords havemaru-mune, jigane looks soft, nagare-hada is common and masame-hada is also seen, andhoso-sugu-ha is popular and skilfully tempered. Boshi is sugu or gentle then turns back in ko-maru with short kaeri and is elegantly tempered with tight a nioi-guchi. The jigane is coveredwith thick ji-nie, sunagashi and hakikake are seen, and the hamon starts with yaki-otoshi.43

Japanese sword researchers have agreed that there is a connection between the workmanshipof the swords preserved in the Shs-in Depository and the Japanese swords that were devel-oped during the Heian Period in the Yamato tradition. Senjuin, Tegai, Taima, Hosho and Shik-kake schools shows common features in their workmanship, and all related to the Ji and Ha ofthe swords of the Shs-in, making the schools in Yamato tradition rightly descended from theswords in the Depository. 44 However there are also differences. On this subject Dr. Honmastates:

Now, I would like to point out differences of the workmanship between old Yamato swords andthe swords of the Shs-in Depository. (1) Tachi by Yamato smiths are in shinogi-zukuri andhave sori. (2) Their jigane look powerful and nie is more emphasised in the ji and ha, sunagashiand hakikake are more conspicuous. (3) There is no tsuchi-me and sen-suki finishes on their

nakago but taka-no-ha, higaki, kiri-yasuri. It must be noticed that the width of their shinogi-ji iswider than that of smiths who lived in other provinces and were active in the same period.OMISSIS After researching the swords of the Shs-in Depository, it becomes clear that theworkmanship of the swords in the Shs-in Depository had an influence on the sword forging ofYamato smiths.45

So with a technical point of view there is a certain continuity between Jokoto and Yamato tradi-tion, even if Im still struggling with the differences in activities that Dr. Honma highlighted here-above. The reason for such differences might lie in the steels used, as seems the one whichthe swords of the Shs-in are made of is softer than the one used later, but also of very highquality and extremely elastic, as attested to by Mr.Ono Kkei, polisher of the blades in the

Shs-in, who states this steel calls to mind the ones of the Naminohira School. Dr. HonmaJunji, Mr. Miyahiri Shhei and Mr.Takahashi Sadatsugu are strongly convinced that the bladesin the Shs-in were made with the Tanren (folding and hammering) method, using a verystrong and elastic steel that we cant replicate except in the carbon content. Mr. Miyahiri be-lieves the steel was heated in a reducing atmosphere at low temperature with a top quality char-coal fire. Such a process was repeated about ten times for the long blades. Mr. Takahashi con-siders these blades the result of remarkable skill even surpassing that of the Kamakura Pe-riod.46 And Mr Miyahiri reported :It is wrong to state that Kamakura Period was the peak of Japanese swords. The uncontrivedlively effect of ji-nie is almost unbelievable.47

We can infer by this that Mr. Miyahiri was convinced of the japanese origin of the blades. Theabove discussion has led us to wonder about the differential hardening process.


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Clay coating

A very debated matter regards the use of a clay-coating process, the Tsuchi-tori, to producetwo areas of different hardness. Differential hardening was already in use by far in China. Asteel single edged broad sword and double-edged steel swords unearthed from the tomb of Em-peror Liu Sheng (d.113 B.C.) at Mancheng (Hebei) gives evidences that the technique of differ-ential hardening was already in use at this time.48 The metallographic examination of the crosssection on one of these swords shows a quench-hardened martensitic structure only in the cut-ting edge that, even if heavily corroded, still shows an hardness of 900 kg/mm2 , while thespine is only pearlite with a small amount of ferrite.49 Notwithstanding this its still debatedwhether the use of clay-coated differential hardening in Japan was within the timeframe werediscussing. Present-day smiths proved to be able to achieve a Yakiba with different hardnessthen the rest of the blade even without Tsuchitori and it has been suggested that the emer-gence of Choji pattern has its roots in this clay-free process in a way that reminds the uzumi-yaki for warabiteto described later. However the Chinese swords and the Japanese ones madefollowing their models show astonishingly well defined Suguha Hamon and well-defined Boshi.The presence of Yakiotoshi is another puzzling detail. Such precision is hard to explain withoutan insulating material for fixing the borders of the Yakiba in such a precise way. It has been

suggested that the original continental technology used oil as insulating material to producethese early swords. It is supposed the process was not different from the one were familiarwith; the blade was coated with oil, then a thin strip of oil was wiped off of the edge of the swordand the blade was heated and quenched to obtain the hamon. Clay coating began to be used inthe mid-Kamakura and that only at the end of Kamakura period all the blades were subject tothe present-day well known process of hardening through clay-coating. In my opinion this the-ory doesnt work, for a simple law of physics. Natural liquids evaporate at too low of a tempera-ture to sustain the Yakiire process. Following the oil theory, Japanese eventually would havahad to use vegetal oil, lacking the present-day chemical industry. I dont know which type ofvegetal oil it is suggested to be used, but I know that the vegetal oil with the highest evaporationpoint Im aware of is Safflower (Carthamus tinctorius ) oil that has its boiling point at 510 F(266 C) while refined Soybean oil evaporates at 495 F (257 C). Im not aware of the boiling

temperatures of animal oils such as the ones produced by whales, so to be safe Ill add the ex-treme liquid material in nature, mercury, that is a metal and evaporates at 674 F (356 C). Alltemperatures considered at the standard atmospheric pressure of 1 bar (meaning the sea-level). Any liquid Im aware of would evaporate in the heating process of Yakiire, that reachesmuch higher temperatures, between 1,341 F and 1,470 F (around 727 to 800 C) or more.50Even considering the statement that the blades of the Shs-in were hardened at low tempera-tures, there is a limit that you cant pass if you want obtain Martensite, as it doesnt occur below1,341 F (727 C). Even considering that the Japanese had a strong enough oil, this solutionwould still give us some problems with the precision showed by Suguha, Boshi and Yakiotoshiof the blades in the Depository. Oil is far from being as good as clay to insulate from heat, cantbe placed in as a thick layer as clay and consequently it couldnt be applied in a thick enoughlayer to obtain the same results we can see in the Shs-in blades. More, in my opinion itwouldnt remain firmly in the desired/required position when the blade is heated in the furnacebecause it is prone to the physics of a liquid material. Just simple gravity might be enough tomove it down and cover the narrow edge, or if we consider placing the blade edge up into thefurnace, it would move down exposing more metal. If the blade touches the hot charcoal itwould ruin the shape of the hardened edge because friction with charcoal would remove the in-sulating coat of oil. To not ruin the insulating coat is a concern even nowadays in the smithingprocess using clay.51 Such an unfortunate event is registered by Suenaga in discussing themetallurgy of sectioned Jokoto, badly rusted, from the Kofun period he studied. He gives rendi-tions, based on photos optically magnified at the best technology available back then. Metal-lographic investigations were effected at the same time.


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He writes discussing the sections of a sword in vertically assembled forging method :It seems that the depicted blade is forged of four pieces of vertically lined-up steel. Picture (4)shows the depiction of the cross-section shown in picture, and we can see the deeply hard-ened edge section. Also along the core, the sides, the area close to the mune, and the muneitself, we can see a martensite structure, and therefore the sharpness of the blade can be imag-ined. However, the white ghost line (i.e. the white line close to the right side) indicates a weaksection of the blade. Anyway, this occurred probably due to an insufficient heat-treatment duringthe forging (that means the steel was too cold).52 (Fig. 12A) and again about 2 different swordswith horizontally assembled forging method: Picture (2) shows the depiction of the cross-section shown in picture. The cutting edge consists of martensite, and one region of the coresection consists of so-called troostite, namely a structure which contains small punctual is-lands of martensite which is caused by hardening. And we can see that one side and an areaclose to the mune consists of troostite too. It is conceivable that this was the result of clay sec-tions peeling off during the heat-treatment..53 (Fig.12B) ...omissis...Picture (4) shows the de-piction of the cross-section shown in picture from the central picture sequence. Somewhataway from the very edge of the sword, a martensite structure is visible, , it seems that thisarea was not sufficiently covered before the yakite treatment and got therefore toohard. (Fig.12C) Its clear from the above statements that Suenaga considers the use of clay-

coating as a matter of fact and never even try to find an alternative explanation. For the men-tioned reasons I dont consider the oil option a viable one to produce blades with the refined de-tails such as the ones in the Shs-in. This, of course, doesnt exclude that certain types ofHamon can be achieved also without clay coating as high-ranking smiths experiment with nowa-days , and that this might have been an alternative technology in the early periods. However inmy opinion its neither a probable scenario for most of the Hamon designs nor for good quality

swords such as the ones in theRepository. In the end, aboutthe use of clay in the differentialhardening process I tend toagree with Honma Junjis opin-ion, who writes :

"...It admits no doubt that theswords preserved in the Shs-

in, like those of later periods,

were fashioned by heating, fold-

ing and hammering repeatedly,

and were tempered (hardened)with the Ji (ground, unhard-ened part) covered with fire clay(tsuchi-tori, clay coating) OMISSIS Furthermore, the

clearly defined regular hamonwhich are to be regarded as the

prototype of suguha, and the

wavy terminating in everted ko-

maru form recalling the style of Nagamitsu of a later period are absolutely impossible without

the tsuchitori process. Concerning these respects the author(Mr. Honma) once asked the opin-ions of the late Mr. Takahashi Sadatsugu and Mr. Miyairi Shhei, both registered as Important

Intangible Cultural Properties (Living national treasures) in the field of swordmaking, showingthem a few examples while Shs-in blades were being polished. Both were strongly in support

of the view that the blades had been made in the Tanren (folding and hammering) and tsuchi-

tori(clay-coating) methods".48

I tend to exclude the blades in the Shs-in were quenched, withor without Tsuchitori, into oil for the presence, amount and quality of activities.

Fig. 12


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The Japanese sword in VIIIth,

IXth

and Xth

century C.E.Wars in the North East and the Warabiteto

The importance of eastern Honshu as source of horses and skilled horseriding archers can beseen also in the revolt of Fujiwara no Hirotsugu, exiled by the Court to Dazaifu after his familylost the control of political key positions due to the extermination caused by the great epidemicof smallpox in 735. The Court had access to the Kanto in order to add skilled soldiers to in-crease the number of mounted archers in its army. Hirotsugu, being limited by his position in thesouthern island of Kyushu, wasnt. Again, the importance of controlling the Kanto was a key to

victory for the court.55Weve already seen in the first part of this work that the Kanto was al-ready shown to have had a relative autonomy from the Yamato Court, but it served as a vassaland was important for the military as a source of horses and mounted archers. Before enteringa specific lecture on how the wars in the East affected the development of the Japanese swordits better to know how the nature of the opponents, the Emishi, affected their fighting. Weknow they were culturally different by Yamato, but archeological evidence tells us that they pos-sessed wet and dry agriculture, metalworking and that they they followed the practice of burying

ranked people in large earthen tombs. The Kanto at this time resemble a snapshot of WesternHonshu in the 6th century, possibly even in the habit of trade warriors and horses to obtain ironand goods, as happened to the west during its relationship with Korean reigns. They consideredthemselves politically independent from the Court.On the other side the Court felt the duty tobring civilization there and surely the fertile lands and wealth of the region played a role too inthe Yamato politic.56 It can be suggested that the first contacts and attempts of civilization were-nt necessarily warlike. Local strongmen (Kuni no Miyatsuko) from the Eastern Provinces suchas the Kenu and the Abe families claimed to have a certain control on them and Yamato Courtheld them responsible for the law and order in the region.57Abe no Omi Hirafu during his expe-ditions founded several district headquarters and palisades at Nutari and Iwafuni, along the Ja-

pan sea. In 708 A.D. the government set up the Dewa Office for the conquest of the NorthernBarbarians, at north of Iwafune, supplying it with weapons and armor. This, together with thebuilding of many palisades, Districts and Provinces tell us that the Region had reached an highlevel of strategic importance in the eyes of the Court.58 However these administrative outpostsshouldnt be equated to firm Yamato control over the region. Possibly irritated by the increasingpresence of the newcomers and by the military buildings, the Emishi revolted in 709 and 720 and 724.59 A great revolt was quelled by Ono no Azumabito using 1000 mounted soldiers from 6different Kanto provinces.60 Relative peace prevailed until 774 but the colonization policy andmilitary reinforcement of the region, such as the building of Fort Taga and Fort Akita in 737, FortOkachi in 759 and Fort Iji in 767, provoked violent actions by the Emishi. 61 Forts could have

been elaborate to the point of including temples, office buildings, storehouses and two differentlevels of walls. This might mean that the functions of these forts were both political and military.The Wars in the Northeast period began in 774 when residents near Fort Monofu in Mutsu

Province revolted.62A total of 5 expeditions, namely in the years 776,788,794,801 and 811,were conducted by the Court in Mutsu and Dewa. Causes for outbreak of hostilities have beenfound on both sides, but the desire of the Court to display its power and greed for land and re-sources are likely the most important, although the need to drive attention away from unwisefiscal policies by the Court 63 and/or the struggle between native chieftains and Court Officialsmust be accounted for64 as when a trusted lieutenant like Iji no Kimi Azamaro, magistrate of Jojidistrict and of Emishi stock revolted against the construction of Fort Kakubetsu just north of FortIji.


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His revolt led to the pillage of buildings of Fort Taga. The wars were extremely harsh, prostrat-ing regions and driving resources from the Bando. For a period the Emishi were able to defeatthe Yamatoarmies with a strike and flee, guerrilla tactics, well fit to the environment and theorganization of their forces. We find interesting accounts about these battles in ancient ac-counts :

the barbarians custom is battle as mounted archers. Ten of our commoners can not rival oneof the enemy. 65

They swarm like bees and gather like ants But when we attack they flee into the mountainsand forests. When we let them go, they assault our fortifications Each of their leaders is asgood as 1.000 men. 66

By 500, in fact, horse trappings and other evidences of horse riding, like Haniwa of horses withsaddle and stirrups, became more and more common in the Kanto and Eastern Honshu 67andJapans leading experts on tombs believe that, by the 500s mounted warfare was probably mostpopular in eastern and northern Honshu.68 and it seems reasonable to think the Emishi estab-lished fighting tactics the Yamato soldiers werent familiar with. This and the perfect familiarity

with the terrain made them feared opponents. The Kanto, of Emishi breed, already proved to bea valuable source of brave soldiers and the Court arrived at the same conclusions as did USArmy, many centuries later : you need an Apache to fight an Apache. But the Emishi had theirown Geronimo. In 784 Emperor Kammu appointed Otomo no Yakamochi to lead another expe-dition, after previous unfruitful attempts. He also ordered that the provinces of the Kanto shouldestablish forces composed of military specialists. This edict was issued during the lowest pointof the confrontation between Yamato and Emishi and is a strong indicator of the growing reli-ance of the Court in military experts from the Kanto. The preparations for war continued until788 when a supposed army of 52.800 foot soldiers , horsemen and porters gathered at FortTaga under the command of the Great General to Campaign in the East, that received thewarning from Emperor Kammu : The safety of the Nation resides in this one expedition.69

From Fort Taga in the spring of 789 the army entered hostile territory, divided into three groups.

2.000 men crossed the Koromo river, searching for the chief bandit Aterui, that is rememberedas the most legendary fighter among the Emishi. After having burned down Sufushi, Ateruishamlet, the Yamato Army was faced by a strong Emishi force. When retreating, they weretrapped in the middle of the river by another Emishi contingent coming from the rear. The errorsof Yamatos Generals from Honshu lead to the loss of 5 generals and a total of 1061 soldiers.No accounts about the number of porters. A great loss of military material occurred as well, ma-terial that went to strengthen the Emishi forces.The defeat at the battle of the Koromo riverwould take its place among Japans military disasters, bitterly remembered as a defeat at thehands of a barbarian people and assured that Taibo no Kimi Aterui had a place in history. TheCourt immediately began to prepare for another expedition. In 791 Emperor Kammu asked formilitary help from the Kanto once again, and appointed Sakanoue no Tamuramaro among theleaders of the army. In 792, 793 and 794 various hamlets in Tohoku surrendered to the100.000 men army (figure surely exaggerated). Now the Court was able to reinitiate their colo-nization efforts. Tamuramaro was able to win because he was able to maintain a unique andtotal command of his forces and was rewarded with the title of Sei I Tai Shogun, The GreatGeneral Who Quells The Barbarians. In 801 Tamuramaro pacified the last territories still givingtroubles. . Aterui surrendered in order to stop the killing of his people and was executed ,18September 802, in Sugiyama, notwithstanding Tamuramaros requests to the Court to save himand let him help to rule the conquered lands.70 The Court had to stop the military conquest ofTohoku because their finances were exhausted. The frontier was quiet until 811, when Fumiyano Watamaro, a pupil of Tamuramaro who had succeeded in the title of Sei I Tai Shogun, leadtroops from Mutsu and Dewa together with submitted Emishi (Ifu, Fushu) to the final conquest ofthe last part of Honshu, after 38 years of warfare. In this period we still find the types of swordsweve already discussed before, but the turning point of the development of Japanese swordsinto what we are now used to refering to as NihonTo is the appearance of WarabiteTo. The old-est example Im aware of has been found in a tomb in Ibaraki, Kanto, and dates to late VIIth cen-tury 71 even if the use of swords by the Emishi is documented as fas as the IVth century. 72


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This seems to match with the theory that Kanto acquired with time a certain technological inde-pendence from the Kinai. According to documents of the late VIII th century period, at the apex ofthe Wars in the Northeast, the Provincial Headquarters manufactured swords, bows, arrows andarmor. A good documented example of the way the wars affected the nature of the weaponsused is surely found in the modification of the Armor from iron to leather.73 This enabled the Ya-mato soldiers to ride in a light and agile way, the same as their opponents following theCounter Response and Symmetry strategy. All changes in weapons design and materials hadto be approved by the Court, and examples had to be sent for approval. 74Even if Ive not beenable to find written evidence, this lets me speculate that local designs could have been sent forapproval to the Court and taken as examples in production of swords by Yamato smiths, eitherfrom the Kanto or the Tohoku, The design of curved Warabiteto, used by Tohoku natives and byKanto soldiers, could have been adopted by the smiths operating for the Yamato Court in theProvincial Headquarters but not only that. The system of Court approval could have been thedoor though which the curvature in the tang (and successively/consequently in the blade) en-tered the western regions, to be applied to KarayoTachi. Reading The Ordinances of Engi,thought to reflect the situation of the IXth century, the diffusion of the idea of curvature couldhave been helped also by the forced relocation of thousands of Emishi from subjugated regionsin almost all the rest of Japan, with the dual target of breaking their resistance in the native

lands and as police for peacekeeping against peasants revolts, even if they themselves re-volted wherever located, revolts often quelled by soldiers of their own breed, such as the bigone that occurred in Dewa in 878.Weve already seen that Kanto had a special position in the Courts politic due to its military im-portance. The Kanto was strong enough to force the Court to gain its support avoiding the directmilitary option, using a Divide et Impera politic. However how could this region have been sostrong under a military aspect ? We know the plain was used for horse breeding, and horseswere valuable goods to trade for iron, but the key is the capacity to smelt and work iron forweapons production. Later well see that Warabiteto shows interesting elements of smithing

technology that haveto be attributed to a

quiet evolved smithingtechnology, as com-plex construction anddifferential hardeningthrough clay coating,technologies alreadyachieved by far in thewest but that still lookuncertain in the Kantoand Tohoku areas,

confirming the gap ofa couple hundred cen-turies we already sug-gested between Kinaiand Kanto / Tohoku,as is to be expected inborder regions. Here

however some differences seem to have occured and a short explanation on ironworking is re-quired.Ironworking was firstly achieved in the Mediterranean area and Middle East. It consistedof smelting ore in small furnaces called bloomeries and then forming the products through

smithing on an anvil. This method was simple and required a small amount of labor It was dif-fused into the Central Asian Steppe where the nomadic Scythians carried the technology intoEastern Siberia by the VIIIth century b.C.

Map 2


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The Chinese invented ferrous techniques on their own, possibly as early as 900 B.C but notreaching proficiency in producing blades and tools from iron ore before the VI th century b.C.75Chinese method involved a much bigger amount of work and huge blast furnaces with more so-phisticated heating technology allowing greater efficiency and production. By the V th centuryB.C. both technologies were available in Korea, but the spreading routes into and down thecountry have not been found yet. Later evidence suggest Koreans adopted the Scythian

method, but some questions are still to be answered hence we cant totally exclude a Chineseinfluence (blue route in fig.13). The evidence of tools for smithing suggest the Japanese fol-lowed the Koreans model of the Scythian tradition of ironworking instead of the Chinese one,76as later Japanese furnaces resemble a variant of a bloomery. The later appearance of anEastern type of furnace might have been either a local achievement or influenced by tradewith Manchuria through the supposed Northern Route. In fact, citations in Nihon Shoki andShoku Nihongiindicate that the Emishi maintained direct contact with peoples across the Sea ofJapan. One such group was the seafaring Mishihase, with whom the Emishi to the north of Ko-shi, along the Sea of Japan coast, exchanged goods at designated beach sites. In 713 Parhae(also known as Bokkai or Balhae), a Korean-Malgal kingdom, was established in Manchuria and

began to seek relations with the Japanese state at Nara. Diplomatic missions from Parhae vis-ited Japan throughout the eighth century. Most landings were at Dazaifu, a military installationand port on the northern coast of Kyushu, but a significant number also came ashore in Dewaand from there made their way to Nara. According to the Shoku Nihongi, some missions wereforcibly detained in Dewa by the Emishi. However, as Nakamura Shuya suggests, Parhae diplo-mats probably had an interest in developing political and economic ties with the Emishi and mayhave voluntarily remained among them. The sea and land routes that gave access to the conti-nent from northern Honshu and Hokkaido are not known. However, a "northern route" and"Parhae route" are mentioned in Shoku Nihongi and suggest that travel through the northernSea of Japan was common. Morita Tei has speculated that the eighth-century Emishi, espe-

cially those living along the northern Honshu coast, were sea traders with an extensive networkof domestic and continental partners.77 By the Kofun period furnaces have been found in vari-ous shapes including circular, elliptical, square and rectangular. Hashiguchi Tatsuya reproducesdiagrams of two iron-production sites in Kyushu.One of these, excavated in Fukuoka , is fasci-nating, for it appears to show a type of bloomery which might be an early ancestor of the Tatarafurnace. . It is dated to a time between the late Kofun and the Nara period. 78 It shows thatbloomeries were in use in early times in the Korea-Japan area, and Donald B. Wagner believes

that the bloomery iron-productiontechnology was learned from Sibe-ria (Scythian method) rather than

from China and as the way whichthe iron-smelting entered Koreahave not been found (yet) and thatChinese themselves might havebeen influenced by the Scythianprocess as well before their devel-opment of iron casting79, the sup-position makes sense to me too.The peculiar construction of thisearly Tatara may have been devel-oped in Korea or Japan in re-sponse to the technical problemscaused by the use of iron sandore.

Fig.13 Supposed dissemination routes of iron-manufacturingtechnology in Japan.


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By the ancient period (8th- 9 th century C.E.) the standard become the rectangular chamber fur-nace but we have also to note that from the early 8th century C.E. in the Eastern provincesthere appeared the type with a half-buried, cylindrical vertically oriented furnace with a diameterof one meter and a width of 1-1.5 meters which is a nice example that has been unearthed inFukushima prefecture (see fig.14). This style spread westward to Kinai, reaching the coast ofthe inland sea in the 9th century and reached Kyushu in the 10th century. These type of furnacesbecame the specific type of the Kanto and Eastern Provinces and was effective enough togive self-sufficiency in iron production for these regions, for the period preceding medievaltimes, when these furnaces disappeared.80 These furnaces suggest that the roots of iron manu-facturing in the two areas might have been different and is a puzzling addition to the Warabite-To, which was another feature specific to the Eastern Provinces that appeared around the sametimeframe. In fact the late 7th , whole 8th and most of the 9th centuries C.E. were characterizedby the emergence and spread, in the Kanto and Tohoku areas first and western regions later, ofa type of sword entirely of Japanese design and, so far, never found on the continent that is

named WarabiteTo be-cause of the design of its

hilt based on curlingbracken shoots. Accordingto the places of excava-tion and goods found to-gether with these swordstheir history was concen-trated mainly in 8th and 9thcentury. Many were un-earthed together with Wa-d coins, showing they

were made after the Wadperiod, 708-715, and the

accompanying grave goods of many were chokut with kamasu-kissaki and Sue ware, that areindicators of the Nara period. These swords although relatively short, show a strong curvature.Masakuni studied more then one hundred specimens showing sori and about 22 show a sorimore than 0,5 cm, and ten of them even a curvature between one and two centimeters. Especi-ally the tsuka has a remarkable sori, and on 52 from the hundred aforementioned pieces, thispart of the sword curves more than one centimeter, and 17 of them show a curve of this part oftwo to three centimeters. When looking at the sori of these warabite-t, the curvature is empha-sized along the tsuka, and this tsuka-sori concerns especially early warabite-t. Warabite-t we-

re intended as a cutting/slashing weapon, and this is clearly seen along the tsuka-sori, the widehaba of the blade around the monouchi area, and the stepped kamasu-kissaki. Also the sori ofthe blade increases the overall curve of the weapon, which results in a better cutting ability. Thesmiths who forged warabite-t applied therefore consciously a sori, and the emphasis of the lat-ter led gradually to the emergence of a tachi-sugata, and therefore the warabite-t has to beregaded in the wider sense as the first step to this development. There are no warabite-twhose blade length exceed those of a tachi with 2 shaku, their longest specimen measures just56 cm in the nagasa but they show over the years a gradual increase in length, and this can

clearly be reconstructed by relics and grave goods.81 The accompanying Wad coins found to-gether with warabite-t at Kumad and Niirone indicate also that the boom of Form I swordsand the emergence of a sori has to be dated to the latter end of the Nara period. Further, wara-bite-t from Mirumae ,Kashizaki and similar examples, which show an overall sori of nearly onecentimeter, date from about the transitional period into the Heian era, and this corresponds withthe subjugations of general Sakanoue Tamuramaro (758-811 C.E.).

Fig.14 Remains of an VIIIth century steel furnace in Fukushima Prefecture.


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Subsequent swords which show a tachi-sugata were found at Kanukida, Kumano-sha, Naga-numa Long warabite-t and kenukigata-gatana in tachi-manner and a sori of up to three centi-meters were found in Hokkaids Ebetsubuto (nagasa 50 cm),Akitas and other sites, and the stu-dy paper of the historic ruins at Gojme places them into the Gangy period (877-885 C.E.), adating which is quite appropriate. When we associate the warabite-t with the subjugations of

the emishi finding their end with Fujiwara no Yasunori (825-895 C.E.) we can assume a flou-rishing period of about 200 years. That means they were mostly in use from the beginning of theeighth, to the end of the ninth, but probably didnt last into the tenth century AD.All warabite-texcavated on Hokkaid like the one excavated in Abashiri, Tokoro as well as the Fujiwara Bowlgrave goods found in Sapporo, point toward the early Heian period as the latest limit, and thatthe swords found among the relics of Eniwa and Usakumai as well as grave goods and emishiswords which date into the Kamakura period must be regarded as rare exceptions. 82 Dr. KidaSadakichi (1871-1931) was of the opinion that warabite-t were of Emishi origin, and that the

swords which wereexcavated

westwards in theKant area were ac-tually brought downby those emishiwhich were alreadycaptured, or to put itinto other words, in-tegrated into thethen Imperial sys-tem. Kida refers to

such swords asfush no tachi (lit.

captured swords).

Dr. Kida suggeststhat from the warabi-te-t of the Shsin

and efu no tachi preserved elsewhere (), that kenukigata-tachi were actually warabite-

t remodelled to fit the tastes of the Yamato people of central Japan. Further, the term fush notachi () was also pronounced as efu no tachi, but in this meaning it was applied to the

swords of the warrior class in contrast to the actual term efu no tachi () which descri-

bed the swords of courtiers and imperial guards. When we look at the research reports of Koda-ma Sakzaemon (1895-1970), Kno Hiromichi, Takakura Shinichir (1902-1990), YonemuraKioe, Sugiyama Sueo, It Nobuo, Got Shuichi, Sonehara Takeyasu or the more recent paperof ba Toshio, it is still unclear if the origins of warabite-t were from the continent or inHonsh. However the accompanying grave goods like magate-gatana or magate-tsu (earlycurved blades) suggest on the basis of analogous items that they belong to the peculiar so-called Okhotsk culture area83 although, it is not clear nor proved if and how warabite-t took

the same course. Such magate-tsu though were also excavated in kofuns at Akayu(Yamagata Prefecture) and Ezuriko (Iwate Prefecture). Further, when looking at the two warabi-

te-t excavated in Akayus Tanukizawa-kofun their interpretation is completely identical with thewarabite-t found in Moroyo, Hokkaid, therefore it can be safely assumed that these swordsmade their way from northern Japan towards southern regions.

Fig.15


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There are currently hardly any eligible reference pieces from the mainland available whichcould shed light on the prototypes or the origins of warabite-t, but a very good indicator is alarge tsu (-tosu) excavated in Kodama in northern Saitama Prefecture . This -tsu (Pic. 16) excavated with haniwa figures of young men as grave goods has a long triangular shapewhich is identical with warabite-t found in these areas. There were also several -to (lit. side

swords) in tomotetsu-zuka (Blade and hilt as a unity formed from the same piece of iron) exca-vated from the Takazuka-kofun of Gunma Prefectures Tomioka region, which have also thesame shape as this -tsu. So it is possible, but yet to be proved, that such large tsu were theprototypes of warabite-t. Dr. Suenaga Masaos assumption that warabite-t were in use fromthe Nara to the early Heian period matches with the already suggested timeframe. Suenagafurther suggests that their usage was restricted to a certain region confirming that warabite-twere hardly used in the western regions. However, it is a common theory that the fact f

Documents

On the Origins of Nihonto