Prince Shōtoku and the Soga family fought and overcame the Mononobe family, who had handled the ancient Japanese religion, and elaborated a plan for national governance based on the unification of the legal codes system and Buddhism. While cooperating with the Soga family, Prince Shōtoku, who was the regent of the Empress Suiko, showed a deep understanding in "foreign" Buddhism,[1] and planned to stabilize national politics through the use of Buddhism. The thought that national peace and security came through the power of Buddhism is called the "making a country safe" thought.