September 01, 1449--(Renxu, August 14th Year of Zhengtong of Ming Dynasty) Emperor Yingzong of Ming Dynasty was held hostage by Wang Zhen and led 500,000 troops to personally conquer the Mongolian Wasi Tribe. That day, he was surrounded by the Washi Army at Tumu Fort (now southwest of Huailai County, Hebei Province), and Yingzong was captured. This is a "change in civil engineering."

In the 14th year of orthodoxy (1449), Zhu Qizhen of Ming Yingzong personally fought against the Wala army and was captured. It took place in Tumubao (now southeast of Huailai, Hebei), hence the name. Zhu Qizhen of Ming Yingzong was only 9 years old when he ascended the throne. The eunuch Wang Zhentang was in charge of the ceremonial warden and controlled the imperial government. At that time, the Mongolian Wa Thorn army in the north was becoming increasingly powerful and posed a threat to the Central Plains. Wang Zhen was not prepared for the northern frontier defense. In July 1449 (the 14th year of orthodoxy), the leader of the Wa Thorn also led his army to attack the Ming Dynasty southward, and the main force was approaching Datong. Under the persuasion and hostage of Wang Zhen, the Ming Yingzong decided to fight in person regardless of the dissuasion of his ministers. Because Wang Zhen missed the military plane, the Ming army was surrounded by the Wa Thorn army On August 31, 1449 (August 14, the 14th year of the orthodox order), the Waxin army launched an attack, and the Ming army collapsed across the board. In the melee, Wang Zhen was killed by Ming General Fan Zhong, and Yingzong was captured by the Waxon army. More than half of the Ming army was killed and injured. This battle is known as the "Transformation of Civil Engineering" in history, also known as the "Transformation of Turkish Fort". The "Transformation of Civil Engineering" seriously weakened the national strength of the Ming Dynasty and became a turning point from the early stage to the middle stage of the Ming Dynasty.

The change of civil engineering shocked the world. Not only did Ming Yingzong become a prisoner of the Wala army, but the entire capital was also in jeopardy. When the crisis was at hand, Yu Qian, who was in charge of the army department, stepped forward. He supported Zhu Qiyu as emperor with civil and military officials, foreign and foreign ministers, and re-established the political core of the Ming Dynasty. He led all parties to defend the capital with the same hatred. With the support of the residents of the capital, he repelled the invading Wala army. He also tried to use Yingzong as a hostage to blackmail and force surrender, but failed. He was also released back to Yingzong in the first year of Jingtai (1450) when the blackmail failed, the attack was attacked and the resistance was attacked. This is the only emperor in history who was captured and returned safely. After being released, Yingzong calmly served as the emperor for six years in Nangong, and finally regained the throne of the emperor in the change of the door in 1457.

Comment: The Ming Dynasty was really chaotic.