Early Kamakura Period — The Birth of the Classical Tachi

The early Kamakura period (Kenkyū through Jōkyū eras, approximately 1190s–1221) was an exceptional age in which the political transformation of establishing a samurai warrior government and the cultural achievement of perfecting the tachi sword form proceeded simultaneously. When Minamoto no Yoritomo established the shogunate in Kamakura (1185), the samurai class seized political authority, and the social demand placed upon swords underwent a fundamental transformation in character. From ceremonially decorative tachi in aristocratic court society to the practical and aesthetic tachi that warriors employed both in actual warfare and in everyday wear—this transition lies at the core of early Kamakura sword culture.

In Yamashiro Province (present-day Kyoto Prefecture), the Awataguchi school came to prominence and established itself as an unshakeable center of sword-making during the early Kamakura period. The most distinctive feature of Awataguchi blades lay in the refinement of the jihada (ground steel). The itame and ko-itame grain flowed with tight density, and the nioi (misty crystalline zones within the hamon) adhered evenly, producing a luminous and transparent jihada surface that established the aesthetic standard later inherited as the foundation of the "Yamashiro tradition." The hamon centered on ko-chōji and suguha, and together with an elegant and dignified sugata (blade silhouette), embodied aristocratic refinement. The blades left by Awataguchi masters—Kunitomo, Hisakuni, Arikuni, and Kuniyasu—are all transmitted to the present day as National Treasures and Important Cultural Properties, attesting to the high level achieved in the early Kamakura period.

In Yamato Province (present-day Nara Prefecture), the Senjūin school, deeply connected to the great temples and shrines of Nara, continued its activities, and later the Tegai school emerged. The traditional characteristics of Yamato blades—masame-grain jihada, vigorous nioi in the hamon, and a robust sugata with tension at the base—were preserved during the early Kamakura period, and fine works were produced as votive offerings to Tōdaiji and Kasuga Taisha. The Yamato smiths simultaneously responded to commissioned blade orders from the Kamakura warrior society, and as a production center they supplied the robust and warrior-oriented tachi that differed from the Yamashiro tradition.

The technically noteworthy development of the early Kamakura period is the diversification of tachi curvature and kissaki (blade tip) styles. The tachi of this period display pronounced koshi-zori (curvature concentrated at the base), and the forceful mid-length kissaki with broad width and compressed inokubi form would undergo major flowering in the subsequent middle Kamakura period. This demonstrates the transition from the slender tachi that had prevailed since the late Heian period toward securing blade width in response to the practical demands of warrior clients. However, the tachi of the early Kamakura period as a whole retain much of the slender and graceful aesthetic of the Heian period, and are clearly distinguished from the grand and powerful tachi of the later middle Kamakura golden age.

The establishment of Minamoto no Yoritomo's samurai government brought significant transformation to sword circulation and votive practices. Yoritomo developed Tsurugaoka Hachimangū as the tutelary shrine of the warrior class and actively conducted the bestowal of armor and fine blades to shrines. This practice spread among the eastern warrior class, and the offering of named blades to temples and shrines became institutionalized in the context of warriors' religious devotion and display of authority—marking the inception of this system. Yoritomo also utilized named blades as gifts for political exchange, and through the bestowal of prized swords to influential retainers, he incorporated blades into the strengthening and maintenance of lord-vassal relations. This reinforcement of the political and ritual functions of swords became fundamental to the formation of the unique sword culture within warrior society.

The Jōkyū Disturbance (1221) was the incident in which the retired Emperor Go-Toba's campaign to overthrow the shogunate was suppressed by the Kamakura shogunate, after which Go-Toba was exiled to Oki. Emperor Go-Toba was known as an enlightened ruler who loved swords and established the goban-kaji (rotating-roster smith) system, summoning master craftsmen from throughout Japan to his court to forge blades for him. After the Jōkyū Disturbance, certain aspects of the sword-forging culture that had flourished under Go-Toba's influence gradually shifted toward Kamakura and became the prehistory of the formation of the Sōshū tradition in the middle Kamakura period. The early Kamakura period thus occupies an indispensable position in the history of the Japanese sword as the period of aesthetic standard formation led by Yamashiro and the age in which the classical tachi first achieved its magnificent maturity.