The Sengoku period or Warring States period in Japanese history was a time of social upheaval, political intrigue, and nearly constant military conflict that lasted roughly from the middle of the 15th century to the beginning of the 17th century. The Sengoku period in Japan would eventually lead to the unification of political power under the Tokugawa shogunate.
The Siege of Osaka (大坂の役 Ōsaka no Eki , or, more commonly, 大坂の陣 Ōsaka no Jin) was a series of battles undertaken by the Tokugawa shogunate against the Toyotomi clan, and ending in that clan's destruction. Divided into two stages (Winter Campaign and Summer Campaign), and lasting from 1614 to 1615, the siege put an end to the last major armed opposition to the shogunate's establishment. The end of the conflict is sometimes called the Genna Armistice (元和偃武 Genna Enbu ), because the era name was changed from Keichō to Genna immediately following the siege.
Oda Nobunaga (織田 信長 Oda Nobunaga (help·info), June 23, 1534 – June 21, 1582) was the initiator of the unification of Japan under the shogunate in the late 16th century, which ruled Japan until the Meiji Restoration in 1868. He was also a major daimyo during the Sengoku period of Japanese history. His work was continued, completed and finalized by his successors Toyotomi Hideyoshi and Tokugawa Ieyasu. He was the second son of Oda Nobuhide, a deputy shugo (military governor) with land holdings in Owari Province. Nobunaga lived a life of continuous military conquest, eventually conquering a third of Japan before his death in 1582. His successor, Toyotomi Hideyoshi, a loyal Oda supporter, would become the first man to unify all of Japan, and was thus the first ruler of all Japan since the Ōnin War.
The Mōri clan (毛利氏 Mōri-shi) was a family of daimyō, descended from Ōe no Hiromoto and established themselves in Aki Province. Their name was derived from a shōen in Mōri, Aikō District, Sagami Province. The generation of Hiromoto began to name themselves Mōri.
After the Jōkyū War, Mōri was appointed to the jitō office of a shoen in Aki Province. During the Kamakura period Mōri was one of prominent Gokenin family due to the fame of their ancestor Hiromoto. At the end of Kamakura Shogunate, Mōri was distant from the Shogunate and showed a favorable attitude to Ashikaga Takauji.
During the war with the Oda clan and the Ikkō-ikki clan, the Mori helped the Ikkō-ikki clan by establishing a naval trade route between each others' provincial docks and harbours, the Oda eventually nullified this by laying siege to the trade ships between the two clans and went to further disrupt trade by attempting to destroy the Mōri fleet, failing on their first encounter in 1571, the second battle took place in 1579 with the Oda sending eight O' Ataka Bune (heavily armoured ships with iron-clad plating) warships to finally destroy the Mori naval threat.
After a struggle between Toyotomi Hideyoshi, who led his army as a general of Oda Nobunaga, the two sides made peace and Mori remained as a daimyo who kept five provinces in Chūgoku. In 1600 Mōri Terumoto led the West Army in the Battle of Sekigahara nominally. The West Army lost the battle and the Mōri clan lost three eastern provinces and moved their capital from Hiroshima to currentday Hagi, Yamaguchi. The newer fief, Mōri han consisted in two provinces: Nagato province and Suo province. Derived from the former, Mōri han was referred often Chōshū han.
Late Hōjō clan (後北条氏 Go-Hōjō-shi ) was one of the most powerful warrior clans in Japan in the Sengoku period and held domains primarily in the Kantō region.
The clan is traditionally reckoned to be started by Ise Shinkurō, who came from a branch of the prestigious Ise clan, a family in the direct employment of the Ashikaga Shoguns. During the succession crisis in the 15th century, Shinkuro became associated with the Imagawa clan via the marriage of his sister to the Imagawa head, who led an army to Kyoto. Through this relationship Shinkuro quickly established a base of power in Kanto.
His son wanted his lineage to have a more illustrious name, and chose Hōjō, after the line of regents of the Kamakura shogunate, to which his wife also belonged. So he became Hōjō Ujitsuna, and his father, Ise Shinkurō, was posthumously renamed Hōjō Sōun.
The Late Hōjō, sometimes known as the Odawara Hōjō after their home castle of Odawara in Sagami Province, were not related to the earlier Hōjō clan. Their power rivaled that of the Tokugawa clan, but eventually Toyotomi Hideyoshi eradicated the power of the Hōjō in the Siege of Odawara (1590), banishing Hōjō Ujinao and his wife Toku Hime (a daughter of Tokugawa Ieyasu) to Mount Kōya, where Ujinao died in 1591.