The Impact of the Ōnin War on Japanese Sword-Making Centers

The Ōnin War (1467–1477), which continued from 1467, fundamentally reshaped the map of Japan's sword-making centers. The roughly 20-year period from the Bunmei era (1469–1487) through the Entoku era (1489–1492) was a pivotal turning point marked by large-scale migrations of sword makers and a reorganization of production centers.

The most significant change was the decline of Kyoto, which had long been the center of Japanese sword-making. As the main battleground of the Ōnin War, Kyoto saw many sword-smithing workshops burned and destroyed, forcing most prominent sword makers to either flee to other provinces or abandon their craft entirely. The sword makers of the Shina and Horikawa schools, based in Yamashiro Province (present-day Kyoto Prefecture), were no exception, and the population of Kyoto's sword makers reportedly plummeted to a fraction of its pre-war levels.

The Historical Concentration of Sword-Making in Bizen Osafune

The most important destination chosen by sword makers who survived the Ōnin War was Bizen Osafune (present-day Osafune-chō, Setouchi City, Okayama Prefecture). Osafune was an established sword-making center dating back to the Kamakura period and had produced renowned smiths such as Mitsutada, Nagamitsu, Kagemitsu, Kanemitsu, Nagayoshi, Morimitsugu, and Yasumitsu.

From the Bunmei era onward, the concentration of sword makers in Osafune accelerated dramatically. Multiple factors drove this development.

First, there was geographic safety. Bizen Province was close to territories directly controlled by the Muromachi shogunate and largely escaped the direct devastation of major warfare. The workshops in Osafune, positioned on elevated terrain, were relatively safe from raids by invaders.

Second, there was stable supply of materials. High-quality iron sand deposits existed near the borders of Bizen, Mimasaka, and Harima provinces, making it easy for sword smiths to obtain raw materials. Furthermore, proximity to the Yoshii River with good shipping access provided advantageous distribution channels for finished products.

Third, there was an existing artisan community. Osafune had accumulated family lineages of sword makers and networks of master-apprentice relationships and fellow craftspeople dating back to the Kamakura period. For sword makers migrating from other provinces, joining such an established community offered significant advantages in acquiring technical knowledge and securing commissions.

Technical Characteristics of Bunmei-Bizen Swords

Bizen swords from the Bunmei and Entoku periods—the generation following the so-called "Bunmei-Bizen" and "Ōei-Bizen"—developed their own distinct technical characteristics.

Diversification of hamon was a prime example. In addition to the "chōji-midare," which had been the hallmark of Kamakura-period Bizen blades, more practical patterns like "gunome" and shallow chōji became increasingly favored. This shift reflected the emphasis on practical battlefield use during the age of warfare.

Changes in blade width were also notable. Bizen blades from the Bunmei era onward became narrower and lighter compared to the robust swords of the Kamakura and Nanboku-chō periods. This change is believed to reflect the tactical demands of the early Sengoku period, when infantry warfare became the dominant form of combat.

The establishment of mass-production systems was also a hallmark of the Bunmei era. To handle large orders, workshop specialization advanced, with different craftspeople now handling separate stages of production—rough forging, heat shaping, quenching, and polishing—rather than a single smith overseeing all processes.

Dispersal of Sword Makers to Mino, Echizen, and Satsuma

Parallel to the concentration in Osafune, there was another significant movement of sword makers after the Ōnin War: their migration to Mino Province (present-day Gifu Prefecture).

During the late Muromachi period, Mino was ruled by daimyo such as the Saito and Toki clans, who actively patronized sword makers. Sword makers who fled Kyoto and Yamato entered Mino, eventually forming the distinctive sword-making culture known as "Mino-den." The Seki smiths rose rapidly during this period, eventually becoming one of the largest sword-making centers during the later Sengoku age.

A similar pattern emerged in Echizen (present-day Fukui Prefecture), where sword makers who migrated from Yamato and Yamashiro became the founders of Echizen sword-making traditions. Smiths descended from Fujishima Tomoshige's lineage established roots in Echizen and shaped the sword-making culture of the Hokuriku region.

In Satsuma (present-day Kagoshima Prefecture), remote geography from the political center actually worked in its favor. Sword makers from Yamato and Bizen entered Satsuma, and under the patronage of the Shimazu clan, laid the foundation for the distinctive "Satsuma Shintō" sword-making culture.

Sword Distribution and Market Structure During the Bunmei and Entoku Periods

Sword distribution also underwent significant change during this era. As Kyoto's sword market shrank, new distribution centers emerged throughout the country.

In Bizen, sword distribution through maritime routes across the Seto Inland Sea became active, with Osafune as the starting point. The supply of swords to Shikoku, Kyushu, and the Kinai region was often handled by middlemen known as "katanaya" (sword merchants).

Another characteristic of this period was the way large bulk orders from daimyo began to drive the market. Powerful daimyo increasingly placed orders for dozens or even hundreds of swords at a time to equip their retainers, which further encouraged the establishment of mass-production systems in Osafune.

Impact on the Present Day—The Prototype of Industrial Clustering

The redistribution of sword makers during the Bunmei and Entoku periods directly shaped the distribution of present-day Japanese sword-making centers. The fact that many sword smiths still congregate in Okayama Prefecture (former Bizen), Seki City in Gifu Prefecture (former Mino), and Okuizumo in Shimane Prefecture (a center of tatara iron-making) reflects their continuation of the clustering structures formed during this era.

Ironically, the destructive Ōnin War ended up creating the modern clustering structure of Japanese sword-making centers. The history of sword makers' migration and reallocation during the Bunmei and Entoku periods stands as testimony to how Japanese sword culture survived and adapted through an era of upheaval.