After the Genpei War and the consolidation of power by Minamoto no Yoritomo, the Kamakura Shogunate was established in 1192 when Yoritomo was declared seii tai-shōgun by the Imperial Court in Kyoto.^[34] This government was termed the bakufu, and it legally held power authorized by the Imperial court, which retained its bureaucratic and religious functions. The shogunate ruled as the de facto government of Japan but kept Kyoto as the official capital. This collaborative arrangement of power was different from the "simple warrior rule" that would be characteristic of the later Muromachi period.^[35]

Family dynamics played an important role in the governance of the shogunate. Yoritomo was suspicious of his brother Yoshitsune, who sought refuge in northern Honshu and was under the protection of Fujiwara no Hidehira. After Hidehira's death in 1189, his successor Yasuhira attacked Yoshitsune in a bid to win Yoritomo's favor. Yoshitsune was killed, and Yoritomo subsequently conquered the territories controlled by the Northern Fujiwara clan.^[35] Yoritomo's death in 1199 led to a decline in the office of the shogun and the rise in power of his wife Hōjō Masako and her father Hōjō Tokimasa. By 1203, the Minamoto shoguns had effectively become puppets under the Hōjō regents.^[36]

The Kamakura regime was feudalistic and decentralized, contrasting with the earlier centralized ritsuryō state. Yoritomo selected provincial governors, known as shugo or jitō,^[37] from his close vassals, the gokenin. These vassals were allowed to maintain their own armies and administer their provinces autonomously.^[38] However, in 1221, a failed rebellion known as the Jōkyū War led by the retired Emperor Go-Toba attempted to restore power to the imperial court but resulted in the shogunate consolidating even more power relative to the Kyoto aristocracy.

The Kamakura shogunate faced invasions from the Mongol Empire in 1274 and 1281.^[39] Despite being outnumbered and outgunned, the shogunate's samurai armies were able to resist the Mongol invasions, aided by typhoons that destroyed the Mongol fleets. However, the financial strain of these defenses significantly weakened the shogunate's relationship with the samurai class, who felt they were not adequately rewarded for their role in the victories.^[40] This discontent among the samurai was a critical factor in the overthrow of the Kamakura shogunate. In 1333, Emperor Go-Daigo launched a rebellion in the hope of restoring full power to the imperial court. The shogunate sent General Ashikaga Takauji to quell the revolt, but Takauji and his men instead joined forces with Emperor Go-Daigo and overthrew the Kamakura shogunate.^[41]

Amidst these military and political events, Japan experienced social and cultural growth starting around 1250.^[42] Advances in agriculture, improved irrigation techniques, and double-cropping led to population growth and the development of rural villages. Cities grew and commerce boomed due to fewer famines and epidemics.^[43] Buddhism became more accessible to the common people, with the establishment of Pure Land Buddhism by Hōnen and Nichiren Buddhism by Nichiren. Zen Buddhism also became popular among the samurai class.^[44] Overall, despite the turbulent politics and military challenges, the period was one of significant growth and transformation for Japan.