Japan’s Warring States: A First Look

The fighting known as the Ōnin War began in Kyoto in 1467 and continued until 1477. It devastated much of the capital and exposed the weakness of the Ashikaga shogunate, the military government based there.

Across the following decades, regional warrior lords built up their own power. Historians call this the Sengoku, or Warring States, age.

The change did not happen everywhere at once. An old government weakened while new regional powers grew.

The emperor and his court remained in Kyoto. So did the shogun, the head of the military government, though his authority over distant regions was increasingly difficult to enforce.

A powerful regional lord, or daimyo, could control castles, command followers and collect revenue within his territory. Another lord might do the same next door.

Even there, power was contested. Temples, local warriors and organized villages could defend interests of their own.

In 1568, Nobunaga advanced from his base at Gifu toward Kyoto. Entering the capital helped him influence the appointment of a shogun; it did not make every regional lord obey him.

His ally Ieyasu held a separate base around Okazaki, farther east. Geography helps explain why cooperation could be useful: each had interests beyond the other’s doorstep.

Keep this dated picture in mind. Bases, alliances and the reach of a lord’s power would change.

A daimyo could not personally guard every road or settle every dispute. He relied on retainers: warriors who served his house, led other men and helped administer its lands.

Some had local families and claims that long predated their service to him. Their knowledge of villages, routes and rival landholders made them valuable.

Command therefore involved more than giving orders. A lord needed people who could turn those orders into action on the ground.

Rice did not march to war, but armies depended on harvests. Land yielded food and revenue; both supported warriors, horses, messengers and the movement of supplies.

Villagers needed part of the crop to live on and seed for the next season. Lords and their representatives demanded dues from the same production.

A larger territory could sustain greater military power. But fighting that emptied villages or damaged fields could also undermine the resources a lord hoped to gain.

After Nobunaga’s death, Ieyasu competed for lands whose previous rulers had fallen. He attracted local warriors partly by promising to protect their existing holdings.

Such an offer mattered to a family trying to keep its home, income and dependants safe. Joining a stronger lord could be a way to preserve these things.

Loyalty was real, but it rested alongside obligations and interests. A lord’s following could grow when his promises looked more reliable than a rival’s.

For a clear example, jump ahead to 1584. Hideyoshi, once one of Nobunaga’s commanders, was extending his authority after Nobunaga’s death. Ieyasu allied with one of Nobunaga’s sons to resist him.

Ieyasu’s forces won an important battle at Nagakute. Yet Hideyoshi’s wider military and political strength remained intact, and Ieyasu’s ally made a separate peace.

Winning a battle had not settled who would lead. The relationship would have to be negotiated again.

Hideyoshi combined pressure with family ties. His sister married Ieyasu, and his mother entered Tokugawa custody as a guarantee while the two sides worked toward an agreement.

In 1586, Ieyasu went to Osaka and publicly accepted Hideyoshi’s authority. He kept substantial lands and military strength, but now stood within a larger hierarchy.

Marriage connected the houses; submission established who stood above whom. Neither should be mistaken for an alliance between independent partners.

The same two men appear in both pictures. What changes is the relationship between them: armed opposition in 1584, then Ieyasu’s acceptance of Hideyoshi’s authority in 1586.

Ieyasu did not disappear from politics when he submitted. His own lands and following gave him a powerful place within the new arrangement.

This is why a timeless chart of “friends” and “enemies” quickly misleads. A useful chart needs dates and a clear description of the connection.

Now return to the years before Hideyoshi’s rise. Nobunaga began as a lord in Owari, near the middle of Japan’s main island, and made Gifu his base in 1567.

He entered Kyoto the following year while backing a claimant to the shogunate. That partnership broke down, and in 1573 he expelled the shogun from the capital.

Nobunaga had overturned an important political centre. He still faced powerful opponents, and unification remained unfinished when he died.

At Gifu, Nobunaga promoted commerce by protecting a market and loosening established guild privileges. Traders had reasons to bring goods and customers into the growing castle town.

This was not simply a story about weapons. A busy town brought supplies, skilled work and commercial connections within reach of a political centre.

Nobunaga did not invent trade, and his local measures did not create free markets everywhere. They show one practical way a lord could strengthen his base.

Nobunaga died in Kyoto in 1582 when his commander Akechi Mitsuhide turned against him at Honnōji temple. The attack broke apart the centre of his command.

Hideyoshi, another of Nobunaga’s commanders, defeated Mitsuhide soon afterward. That victory gave him a strong position, but did not automatically transfer all Nobunaga’s authority to him.

Surviving relatives and commanders still controlled men and land. Hideyoshi’s next task was to outmanoeuvre or overcome these rivals and build a following of his own.

Hideyoshi rose through Nobunaga’s service rather than inheriting his position. Through campaigns and negotiated settlements, he brought the major rival lords under his authority by 1590.

He also became imperial regent, a high court office, rather than shogun. Military command and recognition from the court worked together to strengthen his position.

Many lords retained domains, but could no longer treat their neighbours as freely chosen targets. Unification meant making their power subordinate to a wider authority.

Hideyoshi’s land surveys recorded fields, cultivators and assessed yields. Such information helped define who owed dues and the resources attached to a holding.

His 1588 “sword hunt” ordered the collection of farmers’ weapons. The order linked disarmament to preventing uprisings and keeping cultivation and revenue secure.

These measures sought clearer distinctions between people who farmed and people who fought. They did not instantly create a perfectly fixed society, but they gave government new ways to intervene.

Hideyoshi launched an invasion of Korea in 1592, intending to advance onward into China. Korean resistance and intervention by Ming Chinese forces frustrated that ambition. A second invasion followed in 1597.

The wars devastated communities in Korea. Civilians were killed, homes and fields destroyed, and captives, including skilled craftspeople, taken to Japan.

Japanese forces withdrew in 1598 after Hideyoshi’s death. Withdrawal ended the overseas campaigns, but not the loss of homes, livelihoods and family members.

Ieyasu had been Nobunaga’s ally and then Hideyoshi’s subordinate. In 1590 Hideyoshi transferred him to a large domain in the Kantō region, centred on Edo.

Governing those lands meant placing retainers, securing revenues and organizing an extensive domain. These were resources he could use when the political situation changed.

After Hideyoshi died in 1598, Ieyasu was one of the senior lords charged with supporting his young heir. Cooperation among the leading men soon gave way to rivalry.

In 1600, rival coalitions fought at Sekigahara. Ieyasu led the victorious side. Lords who had served Hideyoshi were found in both camps; this was not simply “Tokugawa against all Toyotomi.”

Victory let Ieyasu confiscate or reduce many opponents’ domains and reward supporters with land. The result changed the balance of power well beyond the battlefield.

Remember the fields and retainers. Redistributing territory also redistributed revenues, obligations and the resources with which a lord could act.

In 1603, the emperor appointed Ieyasu shogun. His military government was based in Edo, while the imperial court remained in Kyoto.

Two years later, Ieyasu passed the title to his son but continued to exercise great influence. The succession helped establish government by the Tokugawa house, not just the personal authority of one victorious commander.

Other daimyo still governed their domains. The emerging order placed them beneath the shogunate rather than removing every regional centre of power.

A rice field needed more than a farmer working alone. Water had to reach it at the right time, and channels and banks needed maintenance. Neighbouring households had reasons to cooperate even when rulers changed.

Women and men cultivated, processed crops and kept households supplied. Village communities also had to deal with dues and demands from above.

For them, politics could arrive as a claim on the harvest or a call for labour, not only as a battle.

In Mino, potters made distinctive wares for the growing world of tea. Clay, glaze, firing and the judgement of the maker shaped objects that people wanted to handle and use.

Merchants connected workshops with customers. Tea gatherings gave bowls and other utensils a place in relationships among wealthy townspeople and warrior patrons.

These activities had their own skills and pleasures. Political upheaval could alter markets and patronage, but it did not explain everything people valued or created.

The destruction of Kyoto during the Ōnin War reminds us what a political struggle could do to a lived-in place. Losing a house also meant losing stored food, tools and the security of a familiar neighbourhood.

Rebuilding required materials, labour and people able to return. A settlement between commanders could stop fighting without replacing those losses.

The invasions of Korea made that gap especially stark. A ruler’s campaign could end while displaced families still faced a profoundly changed future.

Nobunaga’s advance opened a route toward wider command. Hideyoshi, who had served him, built a new supremacy after his death. Ieyasu later established a Tokugawa shogunate.

But this was not a relay in which one man politely handed power to the next. Ieyasu had been Nobunaga’s ally, opposed Hideyoshi and then submitted to him before competing for leadership after his death.

The sequence is easier to remember when the connections remain visible alongside the names.

Sekigahara in 1600 shifted military power. The shogunate established in 1603 gave the Tokugawa a new framework for rule. Yet Hideyoshi’s son and the Toyotomi house still remained in Osaka.

Fighting returned there in 1614–1615, ending with the destruction of the Toyotomi leadership. The new government had not made armed conflict vanish overnight.

The change from Sengoku to Edo was a process of subordinating rival powers and securing succession, not a single moment when everyone became peaceful.

Start with land and the people who worked it. Harvests and revenues sustained retainers; retainers helped a lord command territory. Agreements could join that strength to another house or place it beneath a superior.

A lord's claim therefore had to reach beyond his own residence: into a field, another household's obligations and agreements with neighboring powers.

Each change depended on people who could make claims enforceable. The resulting order offered protection to some households while bringing new demands or destruction to others.