Sakanoue no Tamuramaro and the Emishi Conquest — Early Heian Northeast Administration and Warabite-tō Sword Culture

In the early Heian period, Sakanoue no Tamuramaro (758-811) was a warrior who flourished under Emperor Kanmu's policy of subjugating the Emishi. In 797 (Enryaku 16), he was appointed Seii Taishogun and took charge of governing Mutsu and Dewa.

Emishi Subjugation and Aterui

At that time, the court's control did not extend to the depths of the Tohoku region, and prolonged conflict continued with local Emishi society. Aterui, a leader of the Emishi, repeatedly repelled the imperial court's armies, but after more than a decade of military campaigns against Tamuramaro, he surrendered in 802 (Enryaku 21). It is said that Tamuramaro petitioned for Aterui's life, but according to court deliberation, Aterui and others are said to have been executed.

This series of subjugations marked a turning point in which the ritsuryo state expanded its territory to the Tohoku region, and at the same time was an important moment when the martial culture of the center and the eastern regions came into contact.

Seii Taishogun and Ancient Military Systems

The "Seii Taishogun" was originally an official position of supreme commander of an expeditionary force temporarily appointed for subjugating the Emishi. In later times, from the Kamakura shogunate onward, it became established as a title meaning the head of a samurai government, but in Tamuramaro's time it was purely a military position for warfare against the Emishi. Troops from military units under the ritsuryo system and soldiers conscripted from the eastern regions were mobilized, and vast amounts of military provisions and personnel were deployed for each expedition. The repeated expeditions became a major burden on the national treasury, and it is known that by the late years of Emperor Kanmu, the continuation of these expeditions was debated as one of two major undertakings alongside the construction of Heian-kyo.

Construction of Castle-Fortresses and Management of the Tohoku Region

Besides subjugation, an important achievement of Tamuramaro was the construction of castle-fortresses (josaku). Around the time of Aterui's surrender, Isawa Castle was constructed in what is now Oshu City in Iwate Prefecture, and a garrison headquarters was established there as a base for managing the Tohoku region. Furthermore, Shiwa Castle was built to the north, and the court's domain of control expanded greatly into the Kitakami River basin. Castle-fortresses were not merely military strongholds but also functioned as centers of administration and commerce, serving as places where cultural artifacts from the center and local culture intersected. It is thought that technological exchange in weapons and crafts, including swords, advanced through these points of contact.

Warabite Swords and Eastern Japanese Sword Culture

Among ancient swords from the Tohoku and eastern regions, the warabite sword deserves attention. It has a distinctive shape with a hilt head that is rounded like an unfurled fern frond, and examples have been excavated from archaeological sites and burial mounds from the late Kofun period through the early Heian period. It was a practical single-edged sword, and is thought to have been constructed with consideration for handling on horseback and actual combat.

Because warabite swords are found predominantly in the Tohoku region, they are regarded as weapons deeply connected to the sword culture of the Emishi and other eastern Japanese peoples. As for how the warabite sword was involved in the establishment of the later curved Japanese sword (tachi), this is debated as one of various theories concerning the origins of curvature, and it is not something whose direct lineage can be definitively established.

From Warabite Swords to Kenuki-form Tachi

Looking at the early Heian period from the perspective of sword history, the kenuki-form tachi deserves attention alongside the warabite sword. This sword, which has tweezers-like openings in the hilt portion, is characterized by the hilt and blade being forged as one piece from the same iron (tomogane), and it is known that there is a view that it was born at the intersection of warabite sword lineage and continental-style sword elements. The kenuki-form tachi is an artifact that necessarily appears in overviews of sword history as material showing the transition from the straight swords of ancient times to curved tachi, and the view that cavalry combat experience honed on Tohoku battlefields influenced the shape change of swords has become an influential perspective when considering weapon evolution in this era.

Early Heian as a Transitional Period

The early Heian period was a transitional era when swords transformed from ritual and linear ancient swords into curved, practical swords suited for cavalry combat. The military contact between the center and the eastern regions, symbolized by the Emishi subjugation, becomes important background for considering such practical and localized development of swords. Although this was not an era when specific master smiths or famous swords could be identified, the actual condition of weapons as revealed in excavated materials conveys the state of affairs on the eve of the establishment of the Japanese sword.

Perspectives When Appreciating Excavated Swords

Most warabite swords and kenuki-form tachi are excavated pieces or ceremonial swords of early transmission, and unlike famous swords of later periods, they may not be in a state where hamon and jihada can be appreciated in detail. The main focus of appreciation is placed on form (presence and position of curvature), hilt structure, and overall dimensional balance. When viewing exhibits at a museum, by keeping the following three points in mind, the transformation from straight swords to Japanese swords comes into three-dimensional view.

• Whether the blade and hilt are forged as one piece or made separately
• At what position the curvature begins
• What distinctive features the detailed shaping of the hilt head and openings possess

Tamuramaro Traditions and Influence on Later Generations

After his death, Tamuramaro came to be legendized as an ideal image of a warrior, and numerous temples, shrines, and place-name traditions transmitting stories of Tamuramaro's founding or prayers for victory remain throughout the Tohoku region. It is widely known that Kyoto's Kiyomizu Temple is said to have been founded by Tamuramaro. While a stance of distinguishing historical fact from tradition is necessary, the spread of the tradition itself tells of the profound impression the event of Emishi subjugation left on people of later generations.

Those interested in sword history from ancient times through the Heian period are encouraged to view TOUKENAZA's columns and sword listings to see the changes in sword forms by era.