In July 1399, Zhu Di launched the Battle of Jingyan in an attempt to seize the throne. Although there was the help of Yao Guangxiao, a clever strategist, Zhu Di was invincible and at a disadvantage compared to the huge army of Emperor Jianwen Zhu Yunwen. Emperor Jianwen first sent Geng Bingwen to lead an army of 130,000 to the north in an attempt to defeat Zhu Di in Beiping, but it ended in a defeat. Faced with Zhu Di's strength, Emperor Jianwen sent Li Jinglong to lead an army of 500,000 to attack Zhu Di.
When Zhu Di learned about it, he quickly withdrew his troops in the city, and only ordered his son Zhu Gaochi to lead a small number of troops to hold on to the city. He had long understood that he was short enough to stand up to Emperor Jianwen's huge army. Therefore, he quickly led his army to Daning. Zhu Di camped outside the city of Daning, and then met with his younger brother Zhu Quan alone. Zhu Quan had outstanding performance in military and strategy, and once assisted Zhu Di in attacking Mongolia, and the two brothers tacitly cooperated and made great achievements. Therefore, Zhu Yuanzhang sealed Zhu Di in Beiping, and Zhu Quan was sealed in Daning. Zhu Quan had 80,000 armor soldiers and excellent Duoyan Sanwei cavalry.
Zhu Di urgently needed Zhu Quan's troops, so he went to Daning in person. After entering the city, the two brothers hugged each other affectionately, and Zhu Di asked Zhu Quan to intercede with Emperor Jianwen and complained about Emperor Jianwen's injustice. Zhu Quan was deeply dissatisfied with the unfair treatment he had received under Emperor Jianwen, and wrote a letter of apology for Zhu Di, hoping to obtain Emperor Jianwen's forgiveness. Zhu Quan's trust allowed Zhu Di to put him under house arrest and bring his princess and prince back to Beiping.
However, Zhu Di seized the throne after four years of fighting, without considering the initial promise to Zhu Quan. Zhu Quan wanted to change the southern fiefdoms, such as Suzhou or Qiantang, but Zhu Di refused his request for various reasons. Zhu Quan was sealed to Nanchang and ordered to be the residence of the political secretary. He understands that his ideal of an equal division of the world is wishful thinking, but at least he expects some reward. However, Zhu Di did not give Zhu Quan any reward when he left Nanjing, and only expressed his farewell feelings in a poem. In addition, Zhu Di also sent people to monitor Zhu Quan's every move in Nanchang. Zhu Quan understood Zhu Di's suspicions, avoided interacting with **, and concentrated on chanting poems. Eventually, he became a great Confucian.
Reference historical materials: "History of the Ming Dynasty".