warrior responsible for the consolidation of the power of the Kamakura shogunate, the military dictatorship that ruled Japan from the city of Kamakura in central Japan (1192–1333).

Yoshitoki succeeded his father, Hōjō Tokimasa (q.v.), as regent, making this office the hereditary post of the Hōjō family. Thereafter, although the emperor at Kyōto was the official governmental authority, he ruled through his shogun in Kamakura, whose real power was vested in his regent. In 1219 the Shogun was assassinated, and Yoshitoki replaced him with an infant son of the Fujiwara lineage (a family with high standing among the aristocracy at Kyōto). That move further strengthened the power of the Kamakura government over the Imperial court.

But the court resented usurpation of its power by the Hōjō, and in 1221 the retired emperor Go-Toba (Toba, Go-) tried unsuccessfully to overthrow Yoshitoki in the Jōkyū Disturbance (Jōkyū no ran). Go-Toba and his two sons were exiled, several of his generals were executed, and Yoshitoki established a military headquarters at Rokuhara, just south of Kyōto, to supervise the future activities of the court. The Hōjō family took over many of the estates of the Kyōto court aristocracy, which had hitherto remained outside Hōjō power, and gave them to loyal Kamakura retainers, thus strengthening Hōjō rule and assuring the shogunate's continuing dominion over Japan.