A part of “Folding Screen of the Battle of Sekigahara”
Tokugowo Ieyasu, commander of the Eastern Army, advanced westwards through the valley at Sekigahara. At around noon on the day of battle, Hideaki, Wakizaka and Kikkawa led the turncoats who betrayed Mitsunari to ensure defeat for the Western Army and victory for leyasu.
Date October 21, 1600
Location Sekigahara, Gifu Prefecture, Japan
Opponents (* winner)
*Eastern Army Approx. # Troops 70,000
Commander Tokugawa Ieyasu
#
Western Army Approx. # Troops 80,000
Ishida Mitsunari
The Battle of Sekigahara was the turning point in the Japanese Unification Wars (1550–1615). During the Heian era (794–1192) the emperor ruled Japan from the city of Kyoto. In the 12th century, however, imperial rule was threatened by a new class of warriors known as the samurai, and in the 1180s war erupted between the two most powerful samurai clans. In the Battle of Dannoura (1185) the Minamoto clan was victorious. The emperor sought to buy off Minamoto-no-Yoritomi, leader of the victorious clan, by appointing him commander of the imperial army, in effect creating the position of shogun, with authority to call out the imperial army whenever he deemed it necessary. From this point on, because he controlled the army, the shogun was the real power in Japan. Minamoto soon established an alternate capital at Kamakura, and during the next century and a half Japan was under the shogunate.
Just below the emperor and shogun in importance were the barons known as the daimyo. In theory, these feudal lords owed allegiance to the emperor, but then two powerful daimyo led armies against one another in the Ōnin War (1467–1477). This led to a century-long civil war in Japan that ended only with the appearance of a highly effective military leader, Nobunaga Oda. As a commoner Nobunaga could not become shogun, but he established Yoshiaki Ashikaga in that position and ruled Japan through him. Nobunaga was assassinated in 1592, however, and was succeeded by another very capable military leader in Hideyoshi Toyatomi. Interested in projecting Japanese power beyond the home islands, Hideyoshi first had to unify Japan, which he did in 1590 by defeating the rival Hōjō clan.
Hideyoshi established his capital at Edo (later named Tokyo). Having secured his base and seeking to occupy the samurai, he mounted invasions of Korea during 1592–1593 and 1597–1598. Although initially successful, the invasions failed because of Chinese intervention. Hideyoshi died in 1598.
Toyatomi’s death produced another civil war. Hideyoshi had created a council to rule until his son Hideyori, then only five years old, was old enough to exercise power. Tokugawa Ieyasu, a member of the Minamoto clan, was the most powerful daimyo and regent for the boy, but among his rivals was Mitsunari Ishida, who attempted but failed to assassinate Tokugawa in 1599. Mitsunari’s supporters had control of young Hideyori, but Tokugawa held his mother prisoner. Eventually the diamyo declared their allegiance to one side or the other.
In 1600 when Tokugawa moved north to suppress a rebellion, Mitsunari attempted to gain control of Kyoto. However, his attempts to secure two key castles there met rebuff, and he withdrew southward. Tokugawa now commanded what came to be called the Eastern Army, while Mitsunari’s forces were known as the Western Army. Tokugawa put together a force of about 105,000 men. He directly controlled some 30,000 men, while key allies led another 40,000. Tokugawa’s son commanded another 35,000 men at Edo. Tokugawa ordered his son to follow the main body as he moved against Mitsunari to Sekigahara, a town located at the junction of the coastal and inland roads in a valley formed by four large hills. Mitsunari had a larger force, but Tokugawa, an adroit politician, had courted a number of the daimyo on Mitsunari’s side, hoping that some would defect because Mitsunari was not of noble birth.
Samurai traditionally fought one another with swords, with pikemen and archers in support, but Oda had introduced Western firearms a quarter century earlier, and Tokugawa secured a supply of harquebuses (matchlock firearms). Mitsunari also had some firearms.
On October 20, 1600, Mitsunari’s Western Army of some 80,000 men arrived at Sekigahara and utilized the cover of rain and fog to occupy strong positions in three of its four hills, flanked by two rivers. There Mitsunari and his men awaited the arrival of Tokugawa’s Eastern Army. Hideaki Kobayakawa, a daimyo allied to Ishida, took up position with his men on Matsuo Hill, one of the three hills around the valley, just south of the Fuji River. Although they held a strong position, Mitsunari’s men were tired from a long march, and much of their gunpowder was wet from the rain.
Tokugawa and his men followed but had the advantage that much of the storm had passed when they arrived on the battlefield early on the morning of October 21. Most of their gunpowder was dry. Both armies deployed; Tokugawa placed his allied forces in front and his own army in reserve. A wind scattered the fog at about 8:00 a.m., and the battle commenced with Tokugawa’s army attacking. The fighting went on for three hours with no decision. At 11:00 a.m., however, Mitsunari signaled for Hideaki to attack and drive into Tokugawa’s exposed left flank. Hideaki took no action despite several signals, which were clearly visible to the generals in both armies.
Both sides sensed a change in the battle. At 12:15 p.m. Hideaki decided to switch sides. His men charged from their hillside position, not north into Tokugawa’s left flank but rather into the right flank and rear of Mitsunari’s remaining forces, which now began to roll backward. Another of the daimyos also switched sides against Mitsunari, and by 2:00 p.m. the battle was over. Mitsunari’s army quickly disintegrated, suffering some 40,000 dead. Tokugawa’s side sustained far fewer casualties, leaving him far more powerful.
The Battle of Sekigahara did not end the civil war, but it was the turning point. Fighting continued over the next 15 years, with Tokugawa defeating all daimyo opposed to him. Named shogun in 1603, Tokugawa moved the capital from Kyoto to Edo and became the virtual dictator of Japan. Except for a Christian peasant uprising during 1637–1638, Japan remained peaceful. The shogunate undertook no foreign adventures and instead turned inward. With peace, the samurai were no longer required and gradually lost their warrior skills. The Tokugawa shogunate lasted until the Meiji Restoration of 1867.
References Bryant, Anthony. Sekigahara, 1600. London: Osprey, 1995. Davis, Paul K. 100 Decisive Battles: From Ancient Times to the Present. Santa Barbara, CA: ABC-CLIO, 1999. Samson, George. A History of Japan, 1334–1615. Stanford, CA: Stanford University Press, 1961. Turnbull, Stephen. Battles of the Samurai. New York: Arms and Armour, 1987. ———. The Samurai: A Military History. New York: Macmillan, 1977.
