First, Emperor Jingtai was seriously ill.
In the eighth year of Jingtai, Zhu Qiyu suddenly fell ill and could not go to court. In order to maintain the stability of the situation, some important events in the imperial court need to be conveyed to Zhu Qiyu by Zhu Qiyu's confidant eunuch Xing 'an, and the upcoming New Year celebration has also been cancelled. Although the emperor is the master of power. However, what people need is a living emperor. In case the emperor is gone, he will face the replacement of one courtier after another.
When Zhu Qiyu was ill and seriously ill, the first thing he knew was that he had cured too many diseases and served the eunuchs trusted by the emperor. Although Xing 'an tried to cover up Zhu Qiyu's illness, after all, the news that the emperor was seriously ill got around. The news is undoubtedly like a big earthquake. Courtiers began to feel uneasy, and people's minds changed, because, for some people, this is an opportunity.
? Second, someone inside the door is looking for money.
Shi Heng was the main participant in the door-grabbing uprising, and was once the main hero in defending Beijing. However, due to Zhu Qiyu's emphasis on modesty, Shi Heng, a powerful minister, felt that he was not treated as he deserved. Gradually, Shi Heng had the idea of supporting Zhu Qizhen. In addition to Shi Heng, there are Xu Youzhen, Yang Shan and Cao Jixiang, eunuch of Sili Prison.
These people are dissatisfied with Zhu Qiyu's rule because they are not very proud. They plan to rebuild Zhu Qizhen so that they can gain more rights. Cao Jixiang has accurate information in the palace, while Shi Heng controls the army in Beijing. Yang Shan and others control the Douchayuan, and cooperate with it to carry out the door-to-door relief. Besides, their rebels and Zhu Qizhen, the emperor's father, echoed at a distance in front. In this way, in a panic, the guards in Beijing dare not resist too much, and let Zhu Qizhen and others enter the palace.
? Third, Zhu Qiyu has no heir.
When he was promoted to the throne by Queen Sun and Yu Qian, it was conditional for his nephew to be the Crown Prince. However, after gaining a foothold in Zhu Qiyu, out of selfish desires and for the sake of his descendants, he abolished his nephew Zhu Jianshen's status as a prince and made his son Zhu Jianji a prince. Unfortunately, Zhu Jianji died young, which made everything that Zhu Qiyu did fall short.
Zhu Qiyu's prestige in the imperial court was also lost because of the abolition of his post. Even Yu Qian, who once urged him to ascend to the throne, did not agree with him to abolish his nephew and establish his own son. This made Jingtai Emperor have bad feelings with Yu Qian, Wang Zhi and others. At the same time, in order to carry out his plan, Zhu Qiyu also killed many opponents, which can be said to be unpopular.
Under this series of actions, with Zhu Qiyu's serious illness, all people who were dissatisfied with Zhu Qiyu's rule began to have the psychology of coup. So, Zhu Qizhen became the spokesman for the change of the door, and it came naturally.