In 1435, Emperor Xuanzong died at the age of 38. The 9-year-old Zhu Qizhen ascended the throne with the reign title Zhengtong. This young emperor, who lost his father when he was less than ten years old and grew up with eunuchs, sat on the throne, and the problem of eunuchs' monopoly of power followed. After the reigns of Yongle and Renzong and Xuanzong, Zheng He went west and the Oirat invaded. The Ming Dynasty was troubled by internal and external troubles for a while. Emperor Yingzong Zhu Qizhen followed his ancestors' example and led the army in person, but was defeated in Tumu Fort. A series of events occurred at this time.