 At the Battle of Shigisan, Soga no Umako, who succeeded his father as Ōomi of the Soga clan, eventually killed Mononobe no Moriya, the head of the Mononobe clan, which led to its decline.Umako then installed Emperor Sushun on the throne.As time went on, Sushun eventually became resentful of Umako's power, and wanted him deposed.