Out of his own unique understanding, Zhu Yuanzhang wanted to achieve the purpose of the Fanping Imperial Family by dividing the sons into kings. However, he also knew in his heart that there was a great possibility that there was no one heart between the sons and the emperor, and it was very likely that in the end, the sons would not only not occupy the imperial family, but would fight for the position of the emperor.
To this end, Zhu Yuanzhang, while dividing the sons into kings, made many preventive measures to make up for the shortcomings caused by this sub-sealing system, and his measures mainly included the following aspects:
First, Zhu Yuanzhang ordered his ministers to collect the good and evil deeds of the kings of the Han and Tang dynasties and compile them into a book called "ZhaojianLu", through which he told the sons from time to time, so that they could be vigilant and able to keep to themselves in peace, and strive to complete the tasks of their own clan and imperial family.
Second, he often took his sons through military training, focused on cultivating his sons' military talents, and sent people to urge the kings to practice martial arts diligently. After all, if these clan kings didn't have any military ability at all, how could they do a good job of conducting the clan emperor' house.
For example, in the ninth year of Hongwu, he took the King of Qin, the King of Jin, the King of Yan, the King of Wu, the King of Chu, and the King of Qi to Fengyang to train troops. For Zhu Yuanzhang, he believed that as a son of the imperial family, military ability was a must, but on the contrary, he felt obviously unhappy and dismissive of those sons who liked to dance and ink.
Third, Zhu Yuanzhang repeatedly admonished the kings, and he always had extremely high political expectations for these sons, hoping that they would be humble to their subordinates, treat the people kindly, persuade the people to cultivate, and take the initiative to take the role of insulting the imperial court.
Zhu Yuanzhang often issued edicts to these sons, telling them the great principle of doing things for others, asking them to distinguish between good and evil, to take the holy king of the Fagu Emperor, to work diligently, and to avoid absurdity and no way.
Zhu Yuanzhang was so upset with his sons, but as soon as he died, the contradiction between the king of the clan and the emperor became inseparable, and everything went against his original expectations, and the Battle of Jingnan launched by Zhu Di, the king of Yan, made all this that Zhu Yuanzhang worried about fall short. It really responds to the old saying that man is not as good as heaven!