The Battle of Okehazama (桶狭間の戦い okehazama no tatakai) is a battle that took place on June 12, 1560 between the troops of Imagawa Yoshimoto and the select troops of Oda Nobunaga. Nobunaga won, taking the head of the enemy”s commander-in-chief. This battle caused the decline of the Imagawa clan and the rise of Oda Nobunaga”s prestige and military power.
The Imagawa clan, which ruled the provinces of Suruga and Totomi (present-day Shizuoka Prefecture), wanted to expand its holdings to the west. In the 1550s it succeeded in subduing the small samurai clan Matsudaira, which controlled the Mikawa province (present-day Aichi Prefecture) and was constantly at war with its western neighbor, the Oda clan, owners of Owari Province (present-day Aichi Prefecture). Under the pretext of protecting the weak Matsudaira, the Imagawa family declared war on their enemies. After a series of local battles, it was decided to finally put an end to the Oda. To this end, on June 5, 1560, the 9th head of the Imagawa family, Imagawa Yoshimoto, marched west with a 25,000-strong army.
Meanwhile, the leader of the Oda family, Oda Nobunaga, was only recently able to break up the internal opposition and unite the fragmented lands of Owari province. Because of the long internecine strife, he lost many of his soldiers and was only able to field 3,000 warriors against Imagawa. The forces of the opponents were unequal, so the military leaders of the Oda family prepared to repulse the aggressors under the walls of their own castles.
On June 10, 1560, the advanced Imagawa forces, commanded by the young head of the Matsudaira family, Matsudaira Motoyasu, entered Odaka Castle, whose castellan (steward) had defected to the invading side on the eve of the conflict. The next day Matsudaira”s forces moved all the troops” provisions to the barns of that castle.
Meanwhile, Imagawa”s main army entered Owari territory. Its commander-in-chief, Imagawa Yoshimoto, had set up his headquarters on a low hill in Okehazama. On June 12, at about 3 a.m., on his orders, Matsudaira Motoyasu and general Asahina Yasutomo led their main troops to storm the Oda frontier forts, the fortifications of Washizu and Marune.
Having learned from his scouts that Imagawa Yoshimoto had stayed with a small guard at headquarters, and that most of the enemy army had gone to storm his fortresses, Oda Nobunaga gathered about two thousand soldiers and set out from his Kiyosu fortress to Okehadzama. At 10 a.m. he arrived at the fortifications of Zenzeji Shrine, where he joined up with the units that had been there. At this time, Oda Nobunaga received word that the enemy had captured his frontier forts and was resting after a night-time assault. He also learned that a celebration had been organized at Imagawa Yoshimoto”s headquarters to celebrate the first successful operations. Oda decided to take advantage of the moment and suddenly attack the enemy, who had relaxed too early, and destroy his command center.
Suddenly it rained in the afternoon. Under its cover, Oda Nobunaga led his 3,000 warriors directly to Imagawa”s headquarters. The downpour was so heavy that their column could not be seen from the neighboring mountains. When the rain finally stopped, the sentries at Imagawa”s headquarters discovered that Nobunaga”s almost entire army was right in front of them. Nobunaga took advantage of the general confusion and attacked Imagawa Yoshimoto”s position with all his might. Oda”s warriors quickly ascended the hill of Okehazama. The enemy soldiers fled, dropping their bows, rifles, and flags. Their commander-in-chief, trying to save his life, even abandoned his beloved red palanquin.
Oda Nobunaga”s mounted guards rushed after the retreating men. After they had outgunned the small guard of Imagawa Yoshimoto, they reached Imagawa himself. Imagawa managed to beat off one guard, but at the same moment another came at him, beheading him.
Having lost their commander-in-chief and many talented commanders, the shocked Imagawa forces hastily retreated from Owari province. From this defeat the Imagawa could not recover. In 1561, Matsudaira Motoyasu, a former ally, rebelled against the Imagawa, who changed his name to Tokugawa and formed an alliance with his yesterday”s enemy, Oda. During the next ten years, the Imagawa clan was destroyed by the forces of Tokugawa Ieyasu and Takeda Shingen, and all its lands were divided among its neighbors.
On the other hand, the battle of Okehazama made the name of Oda Nobunaga famous throughout Japan. It strengthened his power in his domain, and made it easier to conquer other lands, as both native and foreign samurai sought to fight under the flags of this “god of war. Although this battle brought victory and fame to Oda, he never again repeated such risky attacks.