Minamoto no Yoriie
Thus, the Genpei War, the final war between Minamoto and Taira had begun. In 1180, Masako's elder brother Munetoki was killed at Battle of Ishibashiyama and Yoshitoki became heir of Hōjō clan. In 1181, Taira no Kiyomori died, leaving the Taira in the hands of his son Taira no Munemori. In 1182, Masako and Yoritomo had their first son, Minamoto no Yoriie, who would be the heir.