北条政子
After Yoritomo's death, Ōe won the trust of his widow, Hōjō Masako, and assisted in the Hōjō clan's seizure of power. He was involved in several important events in the shogunate. In 1199 real power was moved from second shōgun Minamoto no Yoriie to the council of influential "gokenin". In 1203 the shōgun was arrested along with his supporter Hiki Yoshikazu. Hiromoto also helped the Hōjō clan crush enemies as Hatakeyama Shigetada, Hiraga Asamasa and Wada Yoshimori.