Background
Sadamori Taira lived around 940. He was the son of Kunika, senior secretary of Hitachi Province (Ibaraki Prefecture). Sadamori was an ancestor of the Hōjō clan which wielded considerable political power several centuries later, during the Kamakura period.
Career
Sadamori Taira went to Kyoto and served in the Court (around 689). Upon his father being killed by Masakado Taira, he resigned and went back to his native province and sought to destroy Masakado. Because his enemy was overwhelmingly strong, he enlisted the assistance of Hidesato Fujiwara and defeated Masakado (940). For the exploit, he was appointed commander of the Imperial Headquarters in northern Japan. His family thrived.