Genpei War and the rise of the Kamakura shogunate

Under the cloistered emperors the warrior houses of the Taira and the Minamoto rose in the service of the court. In the Hōgen (1156) and Heiji (1159–1160) disturbances the Minamoto leader Yoshitomo was killed and his young son Yoritomo exiled to Izu, and Taira no Kiyomori became the dominant figure in the capital: he was made Grand Minister of State (daijō-daijin) in 1167 and married his daughter to Emperor Takakura. In December 1179 he confined the cloistered emperor Go-Shirakawa, and in 1180 he placed his infant grandson Antoku on the throne. On 5 May 1180 Go-Shirakawa's son Prince Mochihito, with Minamoto no Yorimasa, issued a call to arms against the Taira; the plot was discovered, and on 20 June both died after a battle at the Uji River beside the Byōdō-in.

Mochihito's call reached Minamoto warriors across the country. Yoritomo rose in Izu on 8 September 1180, was beaten at Ishibashiyama, but rallied the eastern warriors and on 26 October entered Kamakura, which he made his headquarters; that autumn a Taira army sent east fled at the Fuji River almost without fighting. The Taira burned the great temples of Nara, but Kiyomori died on 20 March 1181, and famine halted the war for nearly two years. In 1183 Yoritomo's cousin Minamoto no Yoshinaka crushed a Taira army at Kurikara and entered Kyoto, while the Taira fled west with Emperor Antoku and the imperial regalia. Yoshinaka fell out with Go-Shirakawa, and early in 1184 Yoritomo's brothers Noriyori and Yoshitsune defeated and killed him and on 20 March routed the Taira at Ichi-no-Tani. In March 1185 Yoshitsune drove them from Yashima on Shikoku, and on 25 April 1185, in the Kanmon Strait at Dan-no-ura, the Taira fleet was destroyed after some of its allies changed sides; the traditional explanation that a turn of the tide decided the battle is now disputed. The child emperor drowned with his grandmother, Kiyomori's widow Tokiko, and the sacred sword of the regalia was lost in the sea.

Yoritomo had directed the war from Kamakura, where he set up his own organs of government. On 21 December 1185 the court authorised him to appoint military governors (shugo) and stewards (jitō) in the provinces; his quarrel with Yoshitsune ended with Yoshitsune's death at Hiraizumi in 1189 and the destruction of the Northern Fujiwara the same year, and in 1192, after Go-Shirakawa's death, the court appointed Yoritomo sei-i taishōgun. When the Kamakura shogunate began is debated: textbooks long gave 1192, the year of the title; many historians prefer 1185, when the shugo and jitō were authorised; others point to 1180, 1183 or 1190, and Japanese textbooks no longer name a single year. The war was retold in the Tale of the Heike, a literary work rather than a chronicle, whose opening lines on the passing of the proud are among the best known in Japanese literature.