In the twenty-fifth year of Hongwu of the Ming Dynasty (1392 CE), Zhu Biao, the crown prince of the Ming Dynasty, died. Zhu Yuanzhang later made Zhu Biao's son Zhu Yunjiao the grandson of the Ming Dynasty.
After Zhu Yuanzhang's death, his grandson Zhu Yunjiao succeeded to the throne, the historical Jianwen Emperor. In the first year of Emperor Jianwen's ascension to the throne, Zhu Di, the King of Yan, launched the "Battle of Jingnan", and after several years of war, Emperor Jianwen was defeated and Zhu Di seized power.
It's just that many people wonder about this: After Zhu Biao's death, why didn't Zhu Yuanzhang pass the throne to Zhu Di, so as not to avoid the Battle of Jing?
Personally, I feel that Zhu Yuanzhang did not pass the throne to Zhu Di for the following reasons:
Patriarchal influence
The reason why Zhu Biao became Zhu Yuanzhang's heir was not because of any special talents, but because Zhu Biao was the eldest son of Zhu Yuanzhang. Throughout the dynasties, the succession of the eldest son to the throne is a rule that cannot be easily changed - this is the influence of the patriarchal system.
After Zhu Biao's death, according to the provisions of the patriarchal system, zhu Yuanzhang could choose two heirs to the throne at this time: one was his second son, Zhu Zhu, the king of Qin. According to the rules, after the death of the eldest son, the second son can take the throne to exercise the power of the eldest son; the other is the eldest grandson of Zhu Biao, the eldest son of Zhu Biao, who died early, and although Zhu Yunjiao was Zhu Biao's second son, because of the death of his eldest brother, he succeeded Zhu Yuanzhang's eldest grandson in succession.
To sum up: even if Zhu Yuanzhang established Zhu Yunjiao as his grandson and instead made him crown prince, he could only choose Zhu Zhu, the King of Qin. In his fiefdom, Zhu Zhu was boiling with public resentment because of "many good things". Although Zhu Yuanzhang did not read much, he also knew that the Ming Dynasty could not produce a "Qin II", so in contrast, Zhu Yuanzhang could only choose Zhu Yunjiao as his heir.
Zhu Di, on the other hand, is the ineligible candidate for the succession to the throne.
Low probability events
For Zhu Di's talent, Zhu Yuanzhang was not unaware. Therefore, when Zhu Yuanzhang was alive, he also worried that after his death, Zhu Yunjiao would not face the situation that some clan king rebelled and lost the throne. To this end, Zhu Yuanzhang asked Zhu Yunjiao: If your uncle disobeys you, what will happen if you rebel? Zhu Yunjiao said that he would "salute first and then soldier" - not to give his uncles the excuse to rebel, if the other party insisted on rebellion, he was fighting in the army. Zhu Yunjiao's answer was very satisfactory to Zhu Yuanzhang.
But in fact, if Zhu Yunzhuo had really come to power according to his reply to Zhu Yuanzhang, the Battle of Jingnan could have been avoided: because the outbreak of the Battle of Jingnan and the defeat of Emperor Jianwen were both small-probability events.
After Emperor Jianwen ascended the throne, he had long abandoned the previously mentioned "first salute and then soldiers", but carried out a wild killing of the king of the domain, and in the end, Zhu Di believed that Hengzhu was finally dead, so he survived and rebelled. And what Emperor Jianwen did before also made the rest of the clan kings chill, it can be said that the Battle of Jingnan to a certain extent has the attributes of Emperor Jianwen driving fish and making enemies for himself.
Emperor Jianwen's army had many opportunities to kill Zhu Di, but they were all wasted by Emperor Jianwen.
Therefore, whether it is the outbreak of the Battle of Jingnan or the defeat of Emperor Jianwen, in Zhu Yuanzhang's eyes, it is a small probability event, a difficult thing to happen, therefore, Zhu Yuanzhang will not pass the throne to Zhu Di because of the small probability event.