Zhengtong Emperor
Although the Zhengtong Emperor was a prisoner of the Mongols, he became a good friend to both Tayisung Khan Toghtoa Bukha (1416–1453) and his grand preceptor (taishi) Esen. Meanwhile, to calm the crisis at home, his younger brother Zhu Qiyu was installed as the Jingtai Emperor. This reduced the Zhengtong Emperor's imperial status and he was granted the title of "Tàishàng Huángdi" (emperor emeritus).