In the Battle of Okehazama, Japan’s future dictator Oda Nobunaga defeated the numerically superior force of Imagawa Yoshimoto, one of the most powerful regional warlords of sixteenth century Japan. This event is commonly considered the first step in Nobunaga’s rise to national prominence.
In the spring of 1560, Imagawa Yoshimoto, lord of Suruga, Tōtōmi, and Mikawa Provinces (modern Shizuoka and Aichi Prefectures), made the fateful decision to expand his domain westward along the Tōkaidō, the main overland route linking eastern Japan to Kyōto, the seat of the courts of both emperor and shogun. After almost a century of civil wars in Japan, it appeared as if the Imagawa clan was uniquely positioned to succeed in the quest of occupying the capital. If the ruler of a large, prosperous, and well-organized domain were to control Kyōto, the prestige and authority of the center could effectively be linked with the very real power that had developed on the periphery and perhaps put an end to the era now known as the Sengoku Jidai, or Warring
Yoshimoto knew that he was not without competitors. The year before, Nagao Kagetora of Echigo Province (present-day Niigata Prefecture), who would later take the name Uesugi Kenshin, had visited the capital with an entourage of five thousand, paying his respects to EmperorŌgimachi (r. 1557-1586) and Shogun Ashikaga Yoshiteru (r. 1547-1565), who had just returned to Kyōto after nine years of exile. Mōri Motonari, a daimyo (warlord)
One of those smaller domains was that of Oda Nobunaga in Owari Province (present-day Aichi Prefecture), who as shugo-dai (vice governor) of Owari had clashed with Imagawa Yoshimoto when trying to expand eastward into Mikawa. The Matsudaira family, whose domain was in Mikawa, found themselves torn between aligning themselves with the Imagawa and supporting the Oda clan. Matsudaira Motoyasu, heir of the clan’s chieftain, spent his childhood years as a hostage first of the Oda and then of the Imagawa. He saw his first action in 1558 at the age of fifteen, fighting on behalf of the Imagawa against the Oda in western Mikawa. Oda Nobunaga had been trying to consolidate his hold over Owari Province and in 1559 had also gone to the capital for an audience with the shogun, who, according to one source, promoted him to shugo (military governor) of Owari. Yet Nobunaga’s control of his home province remained tenuous at best, and his forces were no match for the vastly superior war machine of the Imagawa.
Imagawa Yoshimoto’s move westward into Owari and beyond was designed to deal once for all with the Oda and other small daimyo blocking his path to the capital. The Imagawa forces, numbering about twenty-five thousand, set out in the fifth month (according to the lunar calendar) of the year Eiroku 3, or in June of 1560. Leaving his son Ujizane (1538-1614) in charge in the domain capital of Sumpu (Shizuoka), Yoshimoto held his first campaign council on June 11 at Kutsukake in Owari, whence he ordered three vanguard units to attack the Oda forts at Narumi, Washizu, and Marume.
At dawn on June 12, Matsudaira Motoyasu commenced his attack on Marume. The fort was soon taken, and its commander Sakuma Morishige perished in battle. Washizu suffered the same fate soon thereafter. This victory effectively eliminated the eastern defenses of the Oda, and Yoshimoto, following Matsudaira Motoyasu’s unit in the direction of Okehazama, decided to rest the main force of his army at nearby Dengakuhazama Gorge.
Nobunaga had received a warning about the impending attack and during the night of June 11 had held a council at his headquarters at Kiyosu Castle. He persuaded his men to take the fight to the enemy against seemingly impossible odds. One chronicle reports that the main force set out from Kiyosu with only six horsemen and two hundred foot soldiers as the smoke from Marume and Washizu was already visible to the east. Nobunaga collected three hundred more men from two of his remaining forts and attacked the enemy atŌtaka Castle, killing no fewer than fifty enemy fighters on horseback.
Having gathered approximately two thousand more men, Nobunaga made his way toward the Imagawa forces. The enemy was in control of Narumi, Marune, and Washizu, but Nobunaga soon received word that the main Imagawa army was resting at Dengakuhazama, with Yoshitomo reportedly celebrating the auspicious start of his campaign and viewing the heads of the vanquished defenders of the castles taken earlier. According to later chroniclers, it was Yanada Masatsuna who pointed out to Nobunaga the futility of trying to engage the enemy contingents at Narumi, since they could easily be reinforced by other Imagawa troops. Instead, he suggested tricking the Imagawa forces at Narumi into believing that the Oda army was camped nearby by hoisting battle flags visible from the fort. In reality, Nobunaga and his men would quietly move around the Imagawa main force toward Dengakuhazama and stage a surprise attack there while the enemy was resting. Facing a force ten to twelve times more numerous than his own, Nobunaga saw the advantages of this stratagem.
As it happened, a thunderstorm accompanied by a torrential downpour helped Nobunaga to conceal his movements from the Imagawa forces. As the storm let up, his men had taken position on the wooded hills surrounding Dengakuhazama Gorge. Nobunaga gave the order to attack. The Imagawa forces were caught by complete surprise. Not ready for battle, confined to a very small space, and literally being forced to fight an uphill battle against an enemy of unknown strength, their ranks quickly disintegrated. Imagawa Yoshimoto was apparently killed before he could put up much of a fight. Later chroniclers stated that he initially assumed a quarrel had broken out among his own men and showed surprise at being surrounded by Oda warriors. Upon learning of the fate of their commander, the survivors of the Imagawa army took to flight. Nobunaga had achieved a truly stunning victory, with only very moderate losses.
In the aftermath of the battle that would enter the history books as the Battle of Okehazama, after a nearby village, Matsudaira Motoyasu—the erstwhile hostage of Nobunaga and now hostage and field commander of the slain Yoshimoto—decided to return to his home province of Mikawa. There he occupied his ancestral castle at Okazaki, resolving to stand his ground against both the Oda in the west and the Imagawa in the east.
Nobunaga would spend the better part of the 1560’s consolidating his hold over Owari. He forged a lasting alliance with Matsudaira Motoyasu, who had changed his name to Ieyasu soon after Okehazama, and his surname to Tokugawa later in the decade. Eventually Nobunaga would accomplish what Imagawa Yoshimoto had attempted. In 1568, he entered the capital at Kyōto and installed Ashikaga Yoshiaki as shogun. Once in control of the capital, Nobunaga proceeded to unify Japan by naked military force, supported by the emperor’s endorsement of his actions.
Although of minor importance from the point of view of strictly military history, the Battle of Okehazama was a crucial turning point in the career of both Oda Nobunaga and Tokugawa Ieyasu, who, along with Toyotomi Hideyoshi, proved to be the pivotal figures in the process of Japan’s reunification in the late sixteenth century. Nobunaga’s victory allowed him to create an independent power base in Owari from which he would launch his successful quest for the capital and national prominence. His quest to unify Japan would ultimately be brought to fruition by Tokugawa Ieyasu with the founding of the Tokugawa shogunate in 1603.
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Hall, John W., et al., eds. The Cambridge History of Japan. Volume 4: Sengoku and Edo. Cambridge, England: Cambridge University Press, 1991. Contains the most comprehensive, up-to-date account of the Sengoku period available in English. -
Hall, John W., Nagahara Keiji, and Kozo Yamamura. Japan Before Tokugawa: Political Consolidation and Economic Growth, 1500 to 1650. Princeton, N.J.: Princeton University Press, 1981. A collection of scholarly essays on sixteenth century Japan. -
Lamers, Jeroen. Japonius Tyrannus. The Japanese Warlord Oda Nobunaga Reconsidered. Leiden: Hotei, 2000. A detailed scholarly account with ample quotations from primary sources. -
Turnbull, Stephen. War in Japan, 1467-1615. Oxford, England: Osprey, 2002. Though not a scholarly work, this book contains a well-researched brief account of the Battle of Okehazama.
1457-1480’s: Spread of Jōdo Shinshū Buddhism
1467-1477: Ōnin War
1477-1600: Japan’s “Age of the Country at War”
Mar. 5, 1488: Composition of the Renga Masterpiece Minase sangin hyakuin
Beginning 1513: Kanō School Flourishes
1532-1536: Temmon Hokke Rebellion
1549-1552: Father Xavier Introduces Christianity to Japan
1550’s-1567: Japanese Pirates Pillage the Chinese Coast
1550-1593: Japanese Wars of Unification
Sept., 1553: First Battle of Kawanakajima
1568: Oda Nobunaga Seizes Kyōto
1587: Toyotomi Hideyoshi Hosts a Ten-Day Tea Ceremony
1590: Odawara Campaign
1592-1599: Japan Invades Korea
1594-1595: Taikō Kenchi Survey
Oct., 1596-Feb., 1597:
San Felipe Incident
Oct. 21, 1600: Battle of Sekigahara