Minamoto no Yoriie
Despite a strong beginning, Yoritomo failed to consolidate the leadership of his family on a lasting basis. Intrafamily contention had long existed within the Minamoto, although Yoritomo had eliminated most serious challengers to his authority. When he died suddenly in 1199, his son Minamoto no Yoriie became "shōgun" and nominal head of the Minamoto, but Yoriie was unable to control the other eastern warrior families. By the early thirteenth century, a regency had been established for the "shōgun" by Hōjō Tokimasa—a member of the Hōjō clan, a branch of the Taira that had allied itself with the Minamoto in 1180. The head of Hōjō was installed as a regent for the "shōgun"; the regent was termed the "Shikken" during the period, although later positions were created with similar power such as the Tokusō and the Rensho. Often the Shikken was also the Tokuso and Rensho. Under the Hōjō, the shogun became a powerless figurehead.