Sekigahara and the Osaka Campaign: Swords in the Age of Unification

The Decisive Battle for the Realm and Swords

On 21 October 1600 (Keichō 5/9/15), the Eastern Army led by Tokugawa Ieyasu and the Western Army led by Ishida Mitsunari clashed at Sekigahara in Mino Province (present-day Sekigahara Town, Gifu Prefecture). This battle, which decided the fate of the realm in a single day, marked the end of the Sengoku period and the dawn of the Edo period. Furthermore, in the Winter and Summer Campaigns of Osaka, which spanned Keichō 19 (1614) to Keichō 20 (1615), the Toyotomi family was destroyed, and the Tokugawa bakufu completed the unification of the country.

This fifteen-year span (1600–1615) was also an extremely important turning point in the history of swords. While the wartime demand for blades of the Sengoku period was rapidly disappearing, a sword culture for an age of peace was on the verge of emerging. Although the forging techniques of kotō were handed down continuously, this was the era of the "Dawn of Shintō," when swordsmiths began to seek a new aesthetic.

Swords of Sekigahara — Blades Used in the Last Great Battle

The swords carried by the warlords who took part in the Battle of Sekigahara were also the culmination of celebrated blades and practical swords that had been tested again and again over the long Sengoku period. Each daimyō supplied or bestowed swords on the samurai under their command, and the battlefield of Sekigahara brought together a wide variety of swords made by smiths from across the country.

Date Masamune fought for the Eastern Army in the Battle of Sekigahara and afterward, while maintaining his relationship with the Tokugawa bakufu, made the Sendai domain prosper. Masamune is known as a connoisseur of swords, and many of his collection and items bestowed on him have been passed down within the Sendai domain. Among the Date family swords held by the Sendai City Museum are works said to have been acquired and possessed by Masamune around this period.

The Osaka campaigns (1614–1615) hold special significance as the last great battles of the Sengoku period. Many of the famous blades held by Toyotomi-side warlords were confiscated or seized after the war and became treasures of the Tokugawa family or of individual domains. Swords as the "relics" of Sengoku warlords came to carry special value and narrative significance in the subsequent culture of sword appreciation.

The Great Migration of Swordsmiths — The Geography of Shintō Born from the Postwar Period

With the end of the wars, swordsmiths across the country made large-scale moves. Swordsmiths who had served daimyō across various regions throughout the Sengoku period moved in search of new patrons within the new postwar order. This "Great Migration of Swordsmiths" determined the geographic distribution of sword-producing regions in the Shintō era.

The most emblematic movement was the activity of Horikawa Kunihiro, the greatest master of the Shintō period. Kunihiro, a native of Hyūga Province (present-day Miyazaki Prefecture), survived the Sengoku period and, in the Keichō era, opened a workshop in Horikawa, Kyoto. Many accomplished smiths emerged from Kunihiro's school, including Izumi no Kami Kunisada, Kawachi no Kami Kunisuke, and Dewa Daijō Kunimichi, forming the lineage of Keichō Shintō.

In Echizen Province (present-day Fukui Prefecture), Yasutsugu, a native of Shimosaka in Ōmi who moved to Echizen as the house smith of Yūki Hideyasu, lord of Kitanoshō in Echizen, established his position as "Echizen Yasutsugu." Yasutsugu was permitted to have the hollyhock (aoi) crest carved into the nakago, and his blades, known as "Aoi Shimosaka," were valued as swords favored by the Tokugawa family. They raised the standing of Echizen as a sword-producing region.

The Date Family and Swords — The Establishment of Sword Culture in the Sendai Domain

Throughout the periods before and after Sekigahara and the Osaka campaigns, Date Masamune demonstrated a deep engagement with sword culture. Masamune was also known as a connoisseur of swords, commissioning works from renowned smiths and acquiring former possessions of Sengoku warlords.

Some of the swords Masamune commissioned or collected are still held by the Sendai City Museum today, serving as valuable witnesses that convey the sword culture of this era to the present. The sword culture of the Sendai domain in the Keichō and Genna eras (1596–1624) vividly depicts the history of swords in the Tōhoku region during the transition from the tensions of the Sengoku period to peace.

The Dawn of the Shintō Era — Toward the Pursuit of Aesthetic Value

After the Summer Campaign of Osaka (1615), lasting peace came to Japan. Once the practical demand of war disappeared, the criteria for evaluating swords began to shift fundamentally from "performance on the battlefield" to "value as works of art." This marked the beginning of the era known as Keichō Shintō.

Shintō-period swordsmiths, while inheriting the techniques of kotō, aimed for brighter, more splendid hamon and lustrous jigane. This direction remained consistent throughout the Edo period, and the lineage from Shintō to Shinshintō opened a new chapter in the aesthetics of nihontō. Sekigahara and the Osaka campaigns were the last great historical turning point for nihontō to fully transform from "tools of war" into "the soul of the samurai and a crystallization of beauty."