In 1590, Japanese warlord Toyotomi Hideyoshi completed his plan for national unification by laying siege to Odawara Castle, the headquarters of the Hōjō family. When Odawara fell, it gave Hideyoshi control of the strategic Kantō region and helped persuade the lords of northern Japan to submit to his authority.

After the assassination of the powerful warlord Oda Nobunaga in 1582, Toyotomi Hideyoshi, one of his trusted generals, sought to carry on his efforts to unify Japan’s disparate domains under a new central authority. Hideyoshi, a man of humble birth, had risen through the ranks through a combination of ambition and tactical skill. In the mid-1580’, Hideyoshi consolidated his position as Nobunaga’s successor and then began a fervent campaign of expansion. In 1587, he moved armies to the southern island of Kyūshū and brought it under his authority. He not only managed to maintain control of the areas that Nobunaga had subjugated but also added to them. Odawara Campaign (1590)
Hōjō Ujimasa
Hōjō Ujiano
Tokugawa Ieyasu
Toyotomi Hideyoshi
Oda Nobunaga
Toyotomi Hideyoshi
Hōjō Soun
Hōjō Ujiano
Tokugawa Ieyasu
Hōjō Ujimasa
Date Masamune

With the subjugation of the warlords of Kyūshū, particularly the Shimazu family, who had posed a significant threat to Hideyoshi’s hegemony, the main forces of opposition lay in the east. The Hōjō family, based in the Kantō Plain in eastern Japan, were a major threat to Hideyoshi. The Hōjō Hōjō family, later[Hojo family, later] , sometimes referred to as the Go-Hōjō or “later Hōjō” were not related to the Hōjō regents who had wielded power from behind the scenes during the Minamoto shogunate in the thirteenth century. Rather, they had been founded by a warlord named Hōjō Soun (1432-1519), whose ascendancy in one of the wealthiest parts of the country is considered by scholars to be a sign of the beginning of a century-long period of civil war known as the Sengoku Jidai, or Warring States Warring States period (Japan, 1477-1600) period. In Hideyoshi’s day, the Hōjō were led by Ujimasa and his son Ujiano, able rulers who were prepared to resist Hideyoshi. Not only were they militarily powerful, but they also were connected by marriage to the powerful warlord Tokugawa Ieyasu, who had been an important ally of Nobunaga and had maintained an uneasy alliance with Hideyoshi after the warlord’s death. Hideyoshi initially tried to get the Hōjō to submit to his authority through diplomatic overtures and negotiation, but when it became clear that the Hōjō were less than willing to negotiate and that Ieyasu would support him in a proposed military campaign, Hideyoshi decided to launch an attack instead.

Odawara is in what is now Kanagawa Prefecture. Before the establishment of the center of Tokugawa rule at Edo, the fortress at Odawara was considered the key to the control of the Kantō region. The Kantō Plain is one of the most fertile parts of Japan. It is also strategically important as a gateway to the eastern part of the country. The fortress at Odawara was considered invincible, but Hideyoshi decided on a strategy that focused more on intimidation than on direct military confrontation. The Hōjō, confident that their castle would not fall, decided on a similar strategy, choosing to pull all of their forces within the fortress’s defenses and not to harass Hideyoshi during his approach. There are reports that Hideyoshi’s forces numbered as many as 200,000 men gathered from all over Japan. The same sources indicate that the Hōjō and their allies could muster only 50,000. In addition, Hideyoshi’s forces, in possession of guns and cannons, had superior armaments. Sources also report that many of the troops on the Hōjō side were peasants who had been pressed into participating in the defense of the castle.

The campaign, as it developed, was not a stressful one for Hideyoshi. In addition to allowing the men to bring their wives or concubines to the battlefield, he provided for their entertainment by organizing tea ceremonies and dramatic performances. The military camp was transformed into something of an extravagant outing. These measures proved particularly frustrating to the Hōjō forces, who felt confined and faced shortages of provisions. While there was sporadic fighting, the main damage done by Hideyoshi was psychological.

The victory at Odawara came about more as a result of Hideyoshi’s ingenuity as a showman and organizer than as a result of military skill. Hideyoshi began construction of a new fortress on a mountain near Odawara, a measure that persuaded many on the Hōjō side that victory was impossible. Hideyoshi’s men first built a series of walls and fences, which gave the impression that the castle had been erected in a single day. The impact on the morale of Hōjō’s men was tremendous.

After a siege of one hundred days, the fortress at Odawara, previously considered to be impregnable, was surrendered. Hideyoshi ordered the suicide of Hōjō Ujimasa as well as his brother and son, sparing those who had fought for them. With this, the Hōjō family were all but eradicated, and Hideyoshi’s victory in the east was complete. By 1591, Hideyoshi’s armies quelled the small pockets of resistance that remained, and the entire country was brought under his control.

The fall of Odawara not only brought the Kantō region under Hideyoshi’s power but also proved to be the decisive step in the unification of the entire country under his authority. It was not necessary for Hideyoshi to conquer every region of Japan physically; he simply needed to secure the allegiance of the local power holders. The warlords of northern Japan had considered the Hōjō domains and their fortress at Odawara to form a buffer between Hideyoshi’s power base in central Japan and their own lands. With the surrender of the Hōjō, powerful northern leaders such as Date Masamune in the Tohoku region had little choice but to submit to Hideyoshi to avoid the invasion of their domains.

After the fall of the Hōjō, Hideyoshi decided to award their lands to Tokugawa Ieyasu. This was not done out of a desire to reward Ieyasu for his loyalty or for his role in the campaign, but rather to remove him from central Japan, where he was a major force. In exchange for his ancestral lands and hard-fought gains to the south of Kyōto, Ieyasu received some of the best agricultural land in the country. After Hideyoshi’s death, Ieyasu was able to rely on his power base in the Kantō region and assembled a fighting coalition with which to challenge his rivals. This led to the Battle of Sekigahara Sekigahara, Battle of (1600) in 1600, which resulted in a victory for Ieyasu. In 1603, Ieyasu solidified his political authority by taking over the office of shogun, marking the beginning of the Tokugawa shogunate, which would survive for more than two and a half centuries. The Kantō region, won as a result of the Siege of Odawara, became the center of power of the new shogunate. The city of Edo, built up near Odawara and renamed Tokyo after the fall of the Tokugawa and restoration of imperial rule in the 1860’, has continued to be the center of Japanese political and economic life.

• Berry, Mary Elizabeth. Hideyoshi. Cambridge, Mass.: Harvard University Press, 1982. The best single volume treatment of Hideyoshi’s career in English. Contains details of his support of the arts and the Kitano tea ceremony.
• Sansom, George. A History of Japan, 1334-1615. 3 vols. Stanford, Calif.: Stanford University Press, 1961. Despite its age, Sansom’s history of premodern Japan is still the most authoritative on the subject in English. Includes detailed coverage of the wars of Hideyoshi’s lifetime, including the Odwara campaign.
• Sato, Hiroaki. Legends of the Samurai. New York: The Overlook Press, 1995. This work contains accounts of the career of Hideyoshi as well as original sources that provide details of his campaigns.
• Turnbull, Stephen. The Samurai Sourcebook. London: Arms and Armour Press, 1998. Offers encyclopaedic coverage of the important figures in the history of the samurai as well as aspects of their military culture including coverage of the siege of Odawara.
• Turnbull, Stephen. Samurai Warfare. London: Arms and Armour Press, 1996. The best English language history of the Japanese wars of unification with coverage of Hideyoshi’s Odawara campaign.

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

June 12, 1560: Battle of Okehazama

1568: Oda Nobunaga Seizes Kyōto

1587: Toyotomi Hideyoshi Hosts a Ten-Day Tea Ceremony

1592-1599: Japan Invades Korea

1594-1595: Taikō Kenchi Survey

Oct., 1596-Feb., 1597:
San Felipe Incident

Oct. 21, 1600: Battle of Sekigahara