The Sengoku Period Explained: Japan's Warring States Era

Understand what the Sengoku period was, how regional lords rose to power, and how three unifiers brought about a new era of peace in Japan.

Published October 19, 2026 at 1:11 PM JST | By Tokyo Paul

Quick answer: The Sengoku period, often called the Warring States era, ran roughly from the Onin War of 1467 to the early 1600s. As the Ashikaga shogunate weakened, regional lords called daimyo competed for territory. Oda Nobunaga, Toyotomi Hideyoshi and Tokugawa Ieyasu then unified the country, and Ieyasu became shogun in 1603.

What "Sengoku" means

Sengoku is usually translated as "warring states" or "country at war." The term describes a period when central authority was weak and regional lords ran their own territories, often defending them with armies. It is also used to name a part of the Muromachi era in the broad sweep of Japanese history, between the Ashikaga shogunate's strong years and the Tokugawa peace.

The word is also a reminder that Japan then was not one political unit in daily practice. People in different regions lived under different lords, laws and tax systems, and that variety is one reason regional history in Japan is so rich today.

Historians do not agree on exact start and end dates. The Onin War of 1467 is the traditional starting point, although some prefer 1454 or 1493. For the end, proposals range from 1568, when Oda Nobunaga entered Kyoto, to 1638, with 1573 and 1600 also widely used. Britannica gives a rough span of 1467 to 1600, which is a convenient guide.

Why the old order weakened

The Ashikaga shoguns of the Muromachi period governed from Kyoto, but they relied on regional governors who had their own followers. Disputes over succession to the shogun's office, including one linked to Ashikaga Yoshimasa's choice of heir, drew powerful families into rival camps.

The Onin War, fought from 1467 to 1477, was led on the two sides by Hosokawa Katsumoto and Yamana Sozen. Both leaders died in 1473, and the war ended in 1477 when western lords withdrew from Kyoto. Much of the capital was damaged, and the shogun's authority in the provinces never fully recovered.

The conflict also spread beyond Kyoto. Lords and their deputies in the provinces began to act on their own, and many local families took the chance to expand their authority. By the end of the century, the political map had been redrawn.

Gekokujo and the rise of the daimyo

In this era, a pattern known as gekokujo, "the low overcome the high," became familiar. Capable retainers sometimes took over from their lords, and new families grew in strength. The daimyo of the Sengoku period ruled their domains on their own authority and not by appointment from the shogun.

Famous examples include Hojo Soun, Uesugi Kenshin and Mori Motonari. These lords built castle towns, issued their own laws, encouraged agriculture and sometimes supported trade, because a well-run domain could support a larger army. Many modern prefectures and cities trace their origins to these regional centers.

Rulers of the time also wrote house codes, lists of rules for their retainers and families. These documents survive in archives and give historians a window into the values and practical concerns of Sengoku society.

Muskets and new connections

In 1543 Portuguese traders reached Tanegashima, an island south of Kyushu, and introduced the matchlock musket. Japanese craftsmen began making guns in large numbers, and foot soldiers called ashigaru became more important in battle. Armies could be larger, and smaller lords found it harder to remain independent.

Contact with Portugal also brought new goods, ideas and the Christian faith. Omura Sumitada became the first Japanese lord to convert, in 1562, and Nagasaki began to develop as a trade port in 1571. Hideyoshi announced the first restrictions on Christianity in 1587, and Catholicism was banned officially in 1614.

Trade in the period was not limited to Europe. Ports in Kyushu and western Honshu were connected to China and Korea as well, and merchants and sailors carried goods, news and technology between the regions.

Three unifiers

Oda Nobunaga won an important victory over Imagawa Yoshimoto at Okehazama in 1560, entered Kyoto in 1568, and removed the last Ashikaga shogun from the capital in 1573. In 1575, with Tokugawa Ieyasu, he won at Nagashino, using musket tactics against a strong cavalry army. He died in 1582 at Honno-ji in Kyoto after a betrayal by Akechi Mitsuhide.

Toyotomi Hideyoshi, who had risen from a humble background, defeated Mitsuhide within about two weeks and continued the work of unification. He subdued Kyushu in 1587, ended the Hojo family's resistance at Odawara in 1590, and issued an edict in 1587 that prohibited private warfare between lords. Ieyasu then won at Sekigahara in 1600.

The three men are often described through a well-known set of comparisons that the Japanese public enjoys repeating. They are best treated as memorable folk sayings and not historical records, but they show how strongly the personalities of the three unifiers are remembered.

The Tokugawa peace

In 1603 Ieyasu became shogun and set up his government at Edo. The Tokugawa period lasted until 1867 and brought more than two centuries of relative peace, a policy of limited foreign contact known as sakoku, and a clear social order. Cities, roads, commerce and the arts grew considerably.

The shift from war to peace changed the role of the warrior class. With fewer campaigns, samurai gradually became administrators and officials, and domain schools taught reading, writing and martial skills side by side. This change in daily life is one of the clearest differences between the Sengoku and Edo periods, and it helps explain why the later era is remembered for scholarship and the arts.

The Sengoku period nevertheless left lasting traces. Castle towns became the basis of many regional cities. Domain boundaries influenced later administrative maps. Stories of the era's leaders shaped literature, theater, television and games, so that even those who have not studied the period often know the names of its main figures.

How to explore the era

There are many ways to see the Sengoku past in person. Castles such as those at Himeji, Matsumoto and Inuyama show different stages of castle design. Battlefield sites, including Okehazama, Nagashino and Sekigahara, have markers and local information. Many regional museums include armor, weapons and documents from the period.

Many local communities keep the memory of this age alive. Annual festivals, reenactments and local museum displays focus on regional lords and the battles of their territories, and they are often a friendly way for visitors to learn.

Many places hold events with costumed processions and local history exhibits. Dates and formats change, so check the current schedule on official tourism pages. When reading, keep in mind that popular novels and dramas, though enjoyable, add story elements, and museum labels or encyclopedias are better guides to what is documented.

Frequently Asked Questions

When was the Sengoku period?

Most sources place it from about 1467, when the Onin War began, to around 1600, when Tokugawa Ieyasu won at Sekigahara. Historians propose several end points, including 1568, 1573, 1600 and 1638, so the exact dates depend on the definition used.

Who were the three great unifiers?

Oda Nobunaga began the process by gaining control of central Japan, Toyotomi Hideyoshi completed unification of the country by 1590, and Tokugawa Ieyasu founded the Tokugawa shogunate in 1603. Their work ended the long era of regional warfare.

Why did firearms matter?

Matchlock guns arrived in 1543 and were soon produced in Japan. They made large infantry forces more effective, which favored lords who could organize and supply bigger armies. This helped larger domains grow, made it harder for small lords to stay independent, and contributed to unification.

Want to go deeper? Tokyo Paul's book Manga-Style Japanese History: Shoguns, Samurai & Sake in 12 Stories is available on Amazon.

Keep Exploring

More guides from Tokyo Paul: Toyotomi Hideyoshi: From Humble Beginnings to Ruler of Japan, Samurai History Timeline: From the Heian Period to Meiji and The Sengoku Era and Tokugawa Ieyasu: How Japan Was Unified.