The Sengoku period (c. 1467 – c. 1603) is a period in Japanese history marked by social upheaval, political intrigue and near-constant military conflict Japanese historians named after the otherwise unrelated Warring States period in China.

It comes to an end when all political power is unified under the Tokugawa shogunate.

During this period, although the Emperor of Japan is officially the ruler of his nation and every lord swears loyalty to him, he is largely a marginalized, ceremonial, and religious figure who delegates power to the Shogun, a noble who is roughly equivalent to a Generalissimo.

In the years preceding this era the Shogunate had gradually lost influence and control over the daimyo (local lords).

Although the Ashikaga shogunate had retained the structure of the Kamakura shogunate and instituted a warrior government based on the same social economic rights and obligations established by the Hōjō, it fails to win the loyalty of many daimyo, especially those whose domains are far from the capital, Heian-kyō.

Many of these Lords begin to fight uncontrollably with each other for control over land and influence over the shogunate.

As trade with China grows, the economy develops, and the use of money becomes widespread as markets and commercial cities appeared.

This, combined with developments in agriculture and small-scale trading, leads to the desire for greater local autonomy throughout all levels of the social hierarchy.

As early as the beginning of the fifteenth century, the suffering caused by earthquakes and famines often serves to trigger armed uprisings by farmers weary of debt and taxes.The Ōnin War (1467–1477), a conflict rooted in economic distress and brought on by a dispute over shogunal succession, is generally regarded as the onset of the Sengoku period.

The "eastern" army of the Hosokawa family and its allies clash with the "western" army of the Yamana.

Fighting in and around Kyoto lasts for nearly eleven years, leaving the city almost completely destroyed.

The conflict in Kyoto then spreads to outlying provinces.

The period culminates with a series of three warlords, Oda Nobunaga, Toyotomi Hideyoshi, and Tokugawa Ieyasu, who gradually unifyJapan.

After Tokugawa Ieyasu's final victory at the siege of Osaka in 1615, Japan settles down into several centuries of peace under the Tokugawa Shogunate, and enters into an era called "Sakoku".