Genki-Tenshō Transitional Era

Peak Demand and the Unification of Japan

Oda Nobunaga, who defeated Imagawa Yoshimoto at the Battle of Okehazama in 1560 (Eiroku 3), subsequently launched large-scale military campaigns toward the unification of the realm. Nobunaga's hegemony expanded rapidly: the Battle of Anegawa in 1570 (Genki 1), the expulsion of the Ashikaga shogunal house in 1573 (Tenshō 1), and the Battle of Nagashino in 1575 (Tenshō 3). Sword demand during this period reached unprecedented proportions, and both Mino and Bizen—the two premier production regions—forged swords continuously, day and night.

The Tenshō era in particular (1573–1592) was a pivotal period in sword history. Oda Nobunaga died in the Honnō-ji Incident in 1582 (Tenshō 10), before implementing the Sword Hunt, and Toyotomi Hideyoshi rose as his successor. In 1588 (Tenshō 16), Hideyoshi issued the Sword Hunt Edict (*Katanagari-rei*), prohibiting peasants, monks, and shrine priests from possessing weapons. This policy institutionalized a clear distinction in status between samurai and commoners and became a crucial turning point in establishing the sword as a symbol of "the samurai's soul," its privileged status now secured.

The Flourishing of Late Mino (Sue-Mino)

The most active smiths during the Genki and Tenshō eras were those of Mino. Centered on Seki in Gifu Prefecture, Mino smithcraft fully utilized the mass-production techniques and organizational structures accumulated throughout the Muromachi period to supply vast quantities of swords to the forces of Nobunaga and Hideyoshi. In particular, the works of Magoroku Kanemoto (called "Seki no Magoroku"), achieved tremendous trust among Sengoku daimyo through their practical cutting ability in actual combat.

Kanemoto's distinctive blade pattern, called "Three Cedars" (*Sanbon Sugi*), consists of three pointed alternating geometric forms arranged in succession, embodying the distinctive characteristics of the Mino tradition. This lucid blade pattern and robust construction possessed a practical aesthetic that could serve as proof of quality even on the battlefield, where complex judgment of authenticity is difficult. Izumi-no-kami Kanesada, known by his style name "Nosada," is renowned as the master craftsman among Seki smiths who left works of the highest artistic refinement.

The Last Radiance of Late Bizen (Sue-Bizen)

Meanwhile, in Bizen, the late-Bizen system established in the Bunmei-Meioei period shone with its final brilliance through the Tenshō era. The Sukesada family continued to supply vast quantities of swords, and smiths such as Tadamitsu and Sue-Sukesada answered the demands of the Sengoku period. However, the smiths of Osafune were already facing a problem: declining quality under the pressure of mass production. The refined *nie* and rich *jigane* texture that characterized the ancient Bizen of the Kamakura and Nanboku-chō periods became difficult to maintain within a mass-production system, and the later works of late Bizen had qualitatively diverged greatly from ancient Bizen.

The Great Yoshii River Flood and the Destruction of Bizen Smithcraft

In 1590 (Tenshō 18), a great flood of the Yoshii River—caused by a massive landslide at Kumayama—struck Bizen. This flood devastatingly destroyed the sword-producing center of Osafune, rendering nearly all the forges of what had been Japan's greatest sword-production center for centuries unusable. The damage from this disaster was catastrophic in terms of human lives, facilities, tools, and transmission of techniques; the sword production of Bizen effectively came to an end with this flood. Although some smiths relocated to other provinces and transmitted their techniques, the organized mass production of the great center of Osafune never revived again.

The Conclusion of the Ancient Sword Age

The Keichō Fushimi Earthquake of 1596 coincided precisely with the beginning of the transitional period from ancient to new-sword (Keichō era, 1596–1615). The loss of Bizen smiths to the earthquake accelerated the necessity for a new sword culture to develop centered on the urban centers of Kyoto, Osaka, and Edo. The Genki and Tenshō eras represent the final fervor of the ancient sword age, and their conclusion marks the moment when one era in the history of the Japanese sword clearly came to an end. Collecting and studying swords from this period is an intellectual adventure that traces the marks that the Sengoku—the most intense period in Japanese history—left inscribed upon the sword.