Question: Emperor Go-Toba was what head of the Imperial Family in Japan?
Sentence (from "Jōkyū War"): Jōkyū War (承久の乱 , jōkyū no ran ) , also known as the Jōkyū Disturbance or the Jōkyū Rebellion, was fought in Japan between the forces of Retired Emperor Go-Toba and those of the Hōjō clan, regents of the Kamakura shogunate, whom the retired emperor was trying to overthrow.
Relevant evidence: No