Battle of Okehazama

On May 19, 1560 (Eiroku 3), the wheels of history turned sharply. Oda Nobunaga, a minor daimyo of Owari, launched a surprise attack against the main camp of Imagawa Yoshimoto, who was advancing on Kyoto with a vast army, and struck him down. This was the Battle of Okehazama.

Imagawa Yoshimoto and the Legendary Yoshimoto Samonji

Imagawa Yoshimoto was no ordinary sengoku daimyo. He was a cultivated man who synthesized court and martial culture at a high level, and also an outstanding statesman who promulgated the Imagawa Kana Mokuroku (territorial code). The blade favored by Yoshimoto was the "Yoshimoto Samonji"—a masterwork that would later be called the "Sozo Samonji."

This blade was forged by Samonji, a Chikuzen swordsmith and one of Masamune's Ten Great Disciples, and is a masterpiece from the Nanboku-cho period. The appellation "Sozo" derives from the Buddhist name of Miyoshi Masanaga, who once possessed this blade. According to tradition, it originally came through the Shogun's household or the Kanrei family to the Imagawa, though it is also said the Imagawa obtained it from another daimyo. Yoshimoto wore this blade as his personal sword and reportedly carried it when he marched toward Kyoto.

After Yoshimoto's death at Okehazama, it was Oda Nobunaga who obtained the blade. Nobunaga had it polished and refinished, then commissioned a gold inlay inscription on the blade: "On the nineteenth day of the fifth month of Eiroku 3, Yoshimoto struck down and this sword taken, inscribed. Oda Owari no Kami Nobunaga." This act of inscribing a war trophy was not merely commemorative; it demonstrated Nobunaga's political intent. The fact that Nobunaga had defeated the mighty Yoshimoto and seized his personal sword as spoils became proof to the realm of Nobunaga's military prowess and extraordinary fortune.

The Battle of Okehazama: Circumstances and Sword Lore

That morning, Yoshimoto was advancing into Owari with some 25,000 troops. Nobunaga's force numbered at most 2,000 to 3,000—a militarily hopeless situation. Yet Nobunaga resolved to charge, launching a surprise attack on Yoshimoto's main camp under cover of a sudden downpour.

Exploiting the moment when the main camp's guards were thin, Nobunaga's forces broke through the chaos and closed in on Yoshimoto. He was ultimately seized and beheaded by Nobunaga's retainer Mouri Shinsuke. Though Yoshimoto drew his blade and wounded a guard, he could not overcome the numerical disparity and fell.

The Yoshimoto Samonji After Okehazama and Its Impact on Sword Culture

The Yoshimoto Samonji that came into Nobunaga's possession subsequently passed from hand to hand. After Nobunaga's death (the Honnō-ji Incident), it passed to Toyotomi Hideyoshi, and then to Tokugawa Ieyasu. Today it is enshrined at Takei Shrine in Kita Ward, Kyoto, and is designated an Important Cultural Property.

The provenance of this blade mirrors the great arc of Japanese history from Okehazama through the Honnō-ji Incident to the establishment of the Edo Shogunate. With each successive unifier of the realm holding the blade, the Yoshimoto Samonji became the very "emblem of heavenly mandate." As a quintessential example of Japan's distinctive sword culture—where a masterwork's changing hands reflects the movement of supreme power—the Yoshimoto Samonji endures in legend.

Nobunaga's Victory and the Transformation of Sword Culture

By securing Owari through his victory at Okehazama, Nobunaga subsequently gathered and confiscated numerous famous blades during his territorial expansion, forging a distinctive sword culture. After taking control of Kyoto, masterwork swords held by the Ashikaga Shogunate and the imperial court flowed into Nobunaga's possession, establishing the foundation of his "sword politics."

Furthermore, Nobunaga's innovative tactics—the organized deployment of firearms and the effective use of common foot soldiers—transformed the blade's role. As firearms proliferated, the sword gradually shifted from primary weapon to the symbolic embodiment of the samurai spirit. Okehazama marked the opening of this transformative era.

At Okehazama (present-day Midori Ward, Nagoya), the battlefield remains are still visible, with Yoshimoto's memorial mound and historical sites commemorating Nobunaga's victory scattered about the landscape. From the perspective of sword history, this place holds sacred significance as the origin of the Yoshimoto Samonji, a legendary masterwork whose story remains told to this day.