Soga clan
He came to the throne with the support of the Soga clan and Empress Suiko, his half sister and the widow of Emperor Bidatsu. Initially, the Mononobe clan, a rival clan of the Sogas, allied with Prince Anahobe, another son of Kimmei, and attempted to have him installed as Emperor. 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.