Simply put, this involves the issue of control over the military.
The so-called gun out of the political power, whoever controls the army, who has the chip to control the political power, ancient and modern, Chinese and foreign, from this point of view, the emperor himself must control the army, otherwise the emperor will not be him, every minute into a puppet or even extermination.
The contradiction lies in the fact that the entire country has a lot of troops, and they are distributed in important towns on the frontier, how can the emperor alone command it? This is like the official government, of course, the emperor wants to rule over the people himself, but if he can't do it, then he can only establish a bureaucratic system, which is conveyed by the officials step by step and exercises his will.
The same is true of the army, if the emperor wants to control the national army, he can only establish an army system, pushed down by the marshals, generals at all levels, and finally to the soldiers. And the rebellion is that a certain general does not listen to the emperor and leads the people below to rebel against the emperor.
Rebellion is actually a drawback of this system, because the emperor's control of the army is indirect, the emperor controls the general, the general controls the soldier, the emperor controls the general and then controls the soldier, and the soldier is not necessarily loyal to the emperor!
The reason why soldiers are not necessarily loyal to the emperor is very simple, there are many volunteers in ancient times, but conscripts, they are not willing to throw their heads and spill blood for the emperor, only a few are eager to make meritorious achievements, the vast majority of them are pulled by the arrest of Zhuang Ding, and being a soldier is a profession for them to support their families.
The emperor is far away in the capital, most of the soldiers have never seen the emperor, and the general is close at hand, coupled with the military combat required soldiers to obey the general (this is a must, the army must ensure the authority of the general, otherwise the war will be a mess), the emperor's control over the soldiers is naturally weaker than the general.
In order to prevent the generals from rebelling, they came up with various methods, in general, there are two major categories, one is to separate the generals and soldiers, so that "the soldiers do not know the generals, will not know the soldiers", and the other is to grasp the grain.
The first method is very difficult to operate, if you play not enough, the general and the soldiers are one, it is equal to not playing; if the play is too hot, such as the separation of the right to unify the troops and the right to train troops, the soldiers trained by this general are handed over to another general to take, the generals and soldiers are wide-eyed, the threat to the imperial power is small, but the same, for the combat effectiveness of the army is greatly affected, after all, which soldier will be willing to give his life to a strange general, fight, always doubt the command of the general, and the general is not familiar with the soldiers, and the dispatch is also very troublesome.
Many of the systems that use this method, such as the Tiger Charm, the Supervision Army, and so on, are all to prevent rebellion.
The second method is to seize the power of the generals to pay grain, grain and this thing, all come from the civil tax, the wool is out of the sheep, the question is who will cut this wool? Was it the central authorities who uniformly cut the hair and sent it to the soldiers? Or did the general himself separate his hair?
When the central government is strong and the finances are abundant, the power to cut wool will not be handed over to the generals, the generals will pay the soldiers, the soldiers are grateful to Dade, and there are only generals left in their eyes, where is the imperial court and the emperor?
However, in a few cases, the central authorities had to hand over appropriate financial power to the military generals, and it was undoubtedly a good idea for the generals to collect grain nearby, which would save the imperial court a large amount of labor and transportation costs, and the army would receive supplies in a more timely manner, and fight more vigorously, which would be a good idea when the finances were not sufficient.
However, delegating financial power is a double-edged sword, and the unity of military generals and financial power can increase the flexibility of the army and enhance the combat effectiveness, but it will also greatly increase the probability of military generals rebelling.
Counting those relatively large rebellions, such as the Anshi Rebellion, that is, because the central government has delegated financial power, military salaries are issued by generals, and soldiers are very supportive of generals, which dares to rebel, otherwise like Zhong Hui, he may be killed by his own subordinates first.
In view of the military coup d'état of the five dynasties at the end of the Tang Dynasty (more than a few), the Song Dynasty carried out a comprehensive weak army operation, what was used to rule by civilian rule, separation of financial power, subordinate restrictions, etc., completely extinguished the signs of rebellion of generals, and subsequent dynasties continued to use it and improved it, so after the Song Dynasty, there were few rebellions by military generals, almost no success, more mutinies, such as the Miao Liu Mutiny.