Task: Question Generation
Input (English): With Yoritomo firmly established, the bakufu system that would govern Japan for the next seven centuries was in place. He appointed military governors, or daimyos, to rule over the provinces, and stewards, or jito to supervise public and private estates. Yoritomo then turned his attention to the elimination of the powerful Fujiwara family, which sheltered his rebellious brother Yoshitsune. Three years later, he was appointed shogun in Kyoto. One year before his death in 1199, Yoritomo expelled the teenage emperor Go-Toba from the throne. Two of Go-Toba's sons succeeded him, but they would also be removed by Yoritomo's successors to the shogunate.
Output (English): What was the name of the emperor that Yoritomo removed from the throne?