Kamakura Middle Period Golden Age

Political Stability and the Maturation of Sword Culture

The Kamakura shogunate, which repelled the plan of Retired Emperor Go-Toba to overthrow it in the Jōkyū War (1221), established political stability over the following decades, and warrior society enjoyed unprecedented prosperity. The Goseibai Shikimoku (1232), enacted by the third regent Hōjō Yasutoki, consolidated the legal foundations of warrior society and prepared the groundwork for cultural maturation. Under this stable political environment, swordsmiths across the provinces were able to devote themselves purely to the pursuit of technique and beauty, and the mid-Kamakura period became a golden age in which the greatest number of masterpieces in the history of Japanese swords were produced.

The swords sought by Kamakura warriors moved away from the decorative court taste of the period before the Jōkyū War. They came to combine practical performance, allowing mounted warriors to fight effectively in open-field combat, with a dignity that showed warrior rank. A powerful overall form, with a somewhat wider body width and increased kasane (blade thickness), was established as the basic form of the tachi. The kissaki was mainly of the short, rounded shape called ikubi-kissaki, which balanced the ability to pierce an opponent's armor with a weight distribution that made the blade easy to swing.

Peak of the Bizen Tradition

The Bizen tradition achieved the most dramatic development in this period. Bizen Province (present-day Okayama Prefecture) was blessed with abundant iron sand from the Yoshii River basin and high-quality pine charcoal. It had been known as a major center of sword production since the late Heian period, and by the mid-Kamakura period both its production scale and its technical level had reached their peak. Osafune Mitsutada is revered as the founder of the Osafune school and perfected the magnificent chōji-midare hamon. Chōji is a hamon element resembling the petals of the clove flower. In Mitsutada's works, chōji with oil-drop-shaped heads are large and splendid, lining up in a continuous chain and creating a profound landscape of nioi.

Mitsutada's son Nagamitsu further developed the large-scale ō-chōji-midare, raising the splendor of Bizen blades to a new level. Nagamitsu's representative work, the Daihannya Nagamitsu, was given a remarkable daizuke (appraised value) of six hundred kan of cash during the Muromachi period, and it is a famous treasure among famous treasures. It is currently a National Treasure owned by the Tokyo National Museum. Nagamitsu's hamon is a completed form that added elegance to Mitsutada's boldness, and later smiths repeatedly used it as a model, as a work showing the summit of the Bizen tradition. Kagemitsu pioneered an original hamon called kataochi-gunome, in which one side drops sharply at a steep angle, further broadening the expressive range of Bizen blades.

Establishment of the Yamashiro Tradition and the Rai School

In Kyoto, the Rai school (Rai-ichiha) established the summit of the Yamashiro tradition. Rai Kuniyuki inherited the techniques of the Yamashiro tradition while opening a unique realm of his own. His son Rai Kunitoshi raised the Yamashiro tradition to a state of perfection in the mid-to-late Kamakura period. Kunitoshi's tachi feature a finely dense jigane with tightly packed koitame skin, on which deep-nie straight hamon (sugu-ha) or small-midare is fired. The high dignity that emanates from the whole is unmatched by others. Many of Rai Kunitoshi's tachi are counted among famous treasures, and they are prized as works in which the balance of the sword's form, the moistness of the jigane, and the brilliance of the hamon are blended into an ideal harmony.

The distinguishing feature of the Rai school lies in the way its jigane is forged. Nie-utsuri stands on a jigane in which koitame is tightly packed, and in part of the jigane a skin with weak forging may appear. This is called Rai-hada and is a point of focus in appraisal. The hamon is based on straight hamon with small-midare and small-chōji mixed in. Compared with Bizen, the nie along the hamon edge is stronger, giving it an introspective beauty that contrasts with the bold character of Bizen.

Deepening of the Yamato Tradition

Under the patronage of the great temples of Nara, the Yamato tradition also saw each of its schools establish its own individuality in the mid-Kamakura period. Tegai Kanenaga, the summit of the Tegai school, represented its peak with a sincere style of straight hamon fired on a powerful masame-hada jigane. The Senjuin school belonged to Tōdai-ji and forged swords in Senju Valley at the foot of Mount Wakakusa. The Taima school forged works with a distinctive surface character, in which masame appears near the kissaki. These Yamato schools were later highly valued, together with the religious authority of Nara, as the tradition of Yamato swords.

Functional Beauty of the Sword Form

An aesthetic element of the mid-Kamakura tachi that cannot be overlooked is the functional beauty of the overall sword form. The koshizori form, in which the peak of the curve lies near the tang (nakago), was born from functional necessity as the shape best suited to drawing the sword while mounted on horseback. Its graceful curved beauty also brings aesthetic pleasure. In appraisal, forms such as ikubi-kissaki and koshizori are clues for identifying the mid-Kamakura period, and works in which these forms are harmoniously beautiful possess a unique dignity not found in any later tachi.

Surviving tachi from the mid-Kamakura period are extremely rare, and many of the signed masterpieces have been designated National Treasures or Important Cultural Properties. The many famous swords that retain the luster of their steel after more than seven hundred years are the supreme achievement of Japan's sword culture. Even though they remain unreachable objects of longing for collectors, experiencing their true nature by viewing the actual pieces in museums is the starting point of Japanese sword research.