・Tomioka Castle was built in 1602 by Terazawa Hirotaka, who was awarded the area of Amakusa for his bravery in the Battle of Sekigahara.
・In 1637, the Shimabara-Amakusa Rebellion took place due to cruel suppression of Christians by Terazawa and the guardians of Tomioka Castle, and severe collection of taxes despite poor harvests resulting from the bad weather. The rebel forces attacked Tomioka Castle but failed to defeat the castle, and then moved to Shimabara.
・After the end of the rebellion, Yamazaki Ieharu became the lord of the Amakusa Domain and ordered the reconstruction of Tomioka Castle. After the period of rule of Magistrate Suzuki Shigenari, the Amakusa lord Toda Tadamasa demolished Hommaru (the keep of the castle) and Ninomaru (the second bailey) of Tomioka Castle in order to lessen the burden imposed on the people of Amakusa for the maintenance and repair of the castle, leaving only Sannomaru (the third bailey), and then he left Amakusa.
・Later, until the Meiji Restoration, Amakusa had been placed under the direct control of the Edo Shogunate. Sannomaru of Tomioka Castle was used as the magistrate’s office and functioned as a base for the ruling of Amakusa.