Minamoto no Sanetomo
After Yoritomo's death, Hōjō Tokimasa, the clan chief of Yoritomo's widow, Hōjō Masako, and former guardian of Yoritomo, claimed the title of regent (shikken) to Yoritomo's son Minamoto no Yoriie, eventually making that claim hereditary to the Hōjō clan. Eventually, Tokimasa deposed Yoriie, backed up his younger brother, Minamoto no Sanetomo, as a new shōgun, and assumed the post of shikken. The Minamoto clan remained the titular shōguns, with the Hōjō holding the real power. In 1219, Sanetomo was assassinated by his nephew Kugyō. Since Sanetomo died childless, the line of shōguns from the Minamoto clan ended with him.