Although there were many eunuchs in Chinese history who brought disaster to the country and the people, no dynasty used eunuchs like the Ming Dynasty. Even in the Tang Dynasty, there was a eunuch general Gao Lishi, but it did not really affect the situation of the entire imperial court. During the Song Dynasty, there were many eunuchs, but they were just some clowns. But by the time of the Ming Dynasty, the eunuchs had become a special group of people, a seemingly humble group that was actually nobler than any normal person. Not only can they get close to the emperor and make the emperor trust them completely, but they can also make their proud ministers become obsessed with them. Those civil officials who dared to argue with the emperor in the court had to bow their heads and submit to softness in front of these eunuchs. They can not only influence the emperor's thoughts and daily life, but also represent the emperor to exert power among the people, and even beat or kill officials at will. On the other hand, in the history of the Ming Dynasty, the emperors of the past dynasties were more reliable and did not directly do anything that harmed the interests of the common people. However, the two major institutions of Jinyiwei and Eunuch often bully the common people for no reason, making the common people hate the imperial court and the royal family. Jinyiwei is powerful and good for face, and eunuchs bully and dominate the market for money, and in the end, this account is counted on the emperor's head.

The reuse of eunuchs was a characteristic of the Ming Dynasty emperors, and there was actually a reason why eunuchs should be reused. As early as the middle and late Southern Song Dynasty, the imperial power had been seriously weakened, and some powerful ministers hardly regarded the emperor in their eyes. For them, the emperor is no longer a high son of heaven, but a puppet who is powerless to be at their mercy. The emperor had no intention of regaining power, because he knew that even if he regained power and would be replaced by someone else in the near future, it would be better to live peacefully without taking his wife. Later, the Mongols occupied the Central Plains, and in the face of the brutal Mongols, the Han had to work together to drive out the Mongols. When the Mongols left the Central Plains, the Han Chinese began infighting again for the sake of the country. Although Emperor Zhu Yuanzhang of Hongwu of the Ming Dynasty won the victory, he did not win completely. The reason why he was able to get the country was because of his efforts and his brothers, and secondly, because of the compromise of local forces. Local forces have examined the three candidates who are most likely to become emperors, one is Zhu Yuanzhang, one is Chen Youliang, and the other is Zhang Shicheng. Zhang Shicheng was born as a salt dealer, dared to fight and had the nickname of the Murder Demon King. The local forces feel that this Zhang Shicheng is not easy to control, and if he becomes emperor in the future, he will not give them the benefits. Chen Youliang was born in a wealthy family, but soon after he started the army, he did something that made the big family dissatisfied. He used the army to rob some uncooperative rich people, not only robbing all the wealth but also killing all the rich families. This made local forces start to worry about whether Chen Youliang would also take action against himself after becoming emperor. Zhu Yuanzhang actually hated the rich who were unkind to the rich, but he didn't shout and kill. After his actions raised and fattened the rich households, he did something to the rich households. It just so happened that the local forces only saw Zhu Yuanzhang's behavior of treating the rich well, but did not see Zhu Yuanzhang's behavior behind him, so the local forces decided to fully support Zhu Yuanzhang as the emperor. With the intervention of these local forces, Zhu Yuanzhang finally became the emperor.

While consolidating his country, Zhu Yuanzhang began to do something to some people. The first target person was Shen Wansan, a wealthy businessman who had funded him at the beginning. Why him? The first is because Shen Wansan is too rich, and the country is too poor and needs money. The second is because Shen Wansan is not a cultural person, and the civil officials and local forces will not react much to him. The third is because Shen Wansan knows too many secrets about Zhu Yuanzhang, and Zhu Yuanzhang can't let Shen Wansan live. Zhu Yuanzhang sent people to fabricate Shen Wansan's crimes, not only taking the opportunity to embezzle Shen Wansan's family property, but also bringing Shen Wansan's family to an end. Afterwards, Zhu Yuanzhang found that raiding the house was really a good thing, which was simpler than fighting a war but had a greater effect. Zhu Yuanzhang fell in love with raiding his house, and from time to time he attacked big families, but he couldn't stop when he wanted to. Only then did the local forces realize that they had made a big mistake, but it was too late. They teamed up to try to secretly attack Zhu Yuanzhang, but they didn't expect Zhu Yuanzhang to be prepared. He secretly trained a group of cronies who were loyal to him, but temporarily took over the positions of officials. Local forces and civil officials thought that if they came up with their killer weapon, the collective dismissal would make Zhu Yuanzhang soften, but they didn't expect Zhu Yuanzhang to take them into the army instead. Zhu Yuanzhang dealt with a few large families led by him, and also killed a few disobedient ministers, temporarily in exchange for a period of stability.

But the good times didn't last long, and local forces instigated Hu Weiyong and others to fight against Zhu Yuanzhang, although Zhu Yuanzhang eliminated these people, but also hurt his own roots. In order to appease these people and not affect the daily operation of the imperial court, Zhu Yuanzhang had to make concessions. Since then, the imperial court has returned to the situation where the emperor and the ministers jointly rule the world. At least when Zhu Yuanzhang was alive, the ministers did not dare to suppress the imperial power too much. Zhu Yuanzhang also knew that after his death, the future emperor would face the coercion of the nobles. Zhu Yuanzhang could only try his best to teach his successor, and at the same time find a way to suppress the power of large families.

After the wars of the early years of the Jianwen Emperor and the Yongle Emperor, the civil officials once again demanded a redistribution of power. Faced with the increasingly excited ministers, Yongle Emperor Zhu Di began to worry about himself and his future descendants. The rise of civil officials is already unstoppable, and Zhu Di can resist for a while, but is it possible for future children and grandchildren to think that he is so strong? What should the emperor do if the civil officials find out that the future emperor is easy to bully? For this reason, Zhu Di was prepared for danger in times of peace and came up with the idea of reactivating Jinyiwei. Jin Yiwei was a war orphan adopted by Zhu Yuanzhang when he was alive. They are not only loyal to Zhu Yuanzhang, but also trained by Zhu Yuanzhang to have the ability to do their best. They can kill the enemy and make meritorious contributions when they go to the battlefield, or they can hide in the people to help Zhu Yuanzhang find out the news and monitor suspicious elements. Zhu Yuanzhang often used these people to spy on and control officials or local magnates. After Zhu Yuanzhang's death, Emperor Jianwen ascended the throne, and he abolished Jinyiwei at the instigation of his ministers. After Zhu Di ascended the throne as emperor, he found that Jinyiwei not only needed to exist, but also needed to be strengthened to counter the civil official group. Zhu Di bargained with the civil officials on the terms, and secretly rebuilt the Jinyi Guard.

Although the appearance of Jinyiwei temporarily curbed the trend of ministers, it did not completely solve the problem. The first is because Jinyiwei is a normal person and has his own relatives and friends, so it is difficult to ensure that the ministers start with their relatives and friends to win over and confuse Jinyiwei. The second is because Jinyiwei is a soldier. It has always been thought that has always emphasized literature over military force, which made Jinyiwei feel inferior and timid when facing ministers. The Third Jinyi Guard was subordinate to the army and was under the control and supervision of the generals. At this time, the military generals have been reduced to the minions of the civil officials, and the military generals can supervise the Jinyi Guard, which means that the civilian officials still have a way to deal with the Jinyi Guard. While Zhu Di separated Jinyiwei from the army and became a yamen who was independent and responsible for himself, he began to standardize the internal rules and regulations of Jinyiwei. Jinyiwei can be hereditary, but it will not easily recruit people from outside, Jinyiwei has its own military law and family law, and only needs to be responsible for the emperor alone.

Although the growth of Jinyiwei made the civil officials a little uncomfortable, the civil officials still had a way to check and balance the Jinyiwei. Jin Yiwei has a family, needs to live, and needs to move outside, so he has to have some contact with civil officials. Gradually, Jin Yiwei began to get closer to the civil officials, and the contradictions between Jin Yiwei and the civil officials gradually decreased, which made Zhu Di start to worry. At this time, Zhu Di's wife, Empress Xu, expressed her opinion, if you want to check and balance the power of civil officials in the real sense, you must find an institution or organization with as few opportunities as possible to contact civilian officials. Zhu Di immediately thought of eunuchs, and only eunuchs don't have to worry about these problems. Eunuchs have no wives and children, so they don't need to worry about their families being coerced by the civil bureaucracy; The eunuchs lived in the palace and had little contact with the outside world, so they didn't have to worry about being bribed by civil officials; The eunuch is the servant of the emperor's family, and can not only be trusted but also used with confidence; Once the eunuch has done something sorry for the master, the master can freely decide whether the eunuch lives or dies without the consent of others; Eunuchs are all royal people in old age, sickness and death, and once someone goes against them, they are against the royal family. This greatly strengthens their self-confidence, and they don't have to worry about someone poisoning them; Civil officials look down on such eunuchs, and they will not have private contact with eunuchs out of personal integrity. Therefore, eunuchs are the best tool to deal with civil officials, and Zhu Di decided to establish a eunuch-based institution to supervise Jinyi Wei and civil officials. Because this institution was built on the east side of the Imperial Palace, the external title was the East Investigation Factory, or simply the East Factory. This was how this famous secret service was established. A new battlefield in which the emperor used eunuchs against civilian officials began.