承久の乱
The Imperial court at Kyoto resented the decline in its authority during the Kamakura shogunate, and in 1221 the Jōkyū War broke out between retired Emperor Go-Toba and the second regent Hōjō Yoshitoki. The Hōjō forces easily won the war, and the imperial court was brought under the direct control of the shogunate. The "shōgun"s constables gained greater civil powers, and the court was obliged to seek the "shōgun"s approval for all of its actions. Although deprived of political power, the court retained extensive estates in Kyoto.