Upon assuming power, he made efforts to erase the legacy of the Jianwen Emperor by removing his supporters from positions of authority and reversing his reforms.

Despite initially rebelling in the name of protecting the rights of the princes, Zhu Di adopted a similar oppressive stance towards them as the Jianwen Emperor and gradually stripped them of their political influence.

His closest advisers were Huang Zicheng, Qi Tai, and Fang Xiaoru,[2] idealistic scholars committed to reform but lacking practical experience in managing the country.

[7] He refrained from openly hostile actions because his three sons had been residing at the Nanjing court since the funeral of the Hongwu Emperor, effectively holding them as hostages.

[6] The emperor considered granting his pleas,[7]supported by Qi Tai, but Huang Zicheng demanded forceful action.

They also successfully thwarted General Song Zhong's attempt to recapture the pass from Kaiping, ultimately defeating and killing him at Huailai.

[10] In these communications, he stated that he had taken action to put an end to internal political disorder and confusion, to uphold the Hongwu Emperor's statutes and laws defining the duties of princes, and that he was motivated by respect for his late father.

He also asserted that he had no interest in the throne, but as the eldest living son of the deceased emperor and Empress Ma, he was obligated to restore the law and legality that had been subverted by the new government.

Zhu Di was a decisive and exceptionally capable commander, leading an elite group of Ming soldiers, including a large contingent of Mongolian cavalry.

On the other hand, the imperial party was weakened by the indecisiveness and poor coordination of its commanders, as well as the conflicting views between those who supported aggressive tactics and those who favored conciliatory approaches.

[14] The war officially began in August 1399 when the emperor appointed Marquis Geng Bingwen (c. 1339–1404), a retired experienced general, as the commander of the troops tasked with suppressing the rebellion.

[12] In response to Geng's failure, the court replaced him with General Li Jinglong,[c] but the new commander did not improve the management of the troops.

In December 1399, Zhu Di issued another proclamation accusing the emperor's associates, Qi Tai and Huang Zicheng, of crimes.

This delay resulted in many soldiers from the south perishing due to exhaustion from the long march and harsh weather conditions.

The government army suffered significant casualties and was forced to retreat in disarray to Dezhou on 30 May, and then continued south to Jinan.

[16] In early June, Zhu Di launched an offensive by marching on Dezhou and was successful in crushing Li Jinglong's exhausted troops in front of the city and occupying it.

[16] The city was defended by Ping An and Sheng Yong (盛庸), two capable government generals, with the support of Shandong governor Tie Xuan.

[20] As a result of these events, the emperor dismissed Li Jinglong and appointed Sheng Yong, who had been promoted to marquis, as the new "commander-in-chief for the pacification of the rebel forces".

[19] From the autumn of 1400, Zhu Di, influenced by information from eunuchs and other supporters remaining at the Nanjing court, focused on a war of attrition.

[21] On 9 and 10 January, the government army successfully defeated the rebels who were attacking Dongchang, a city located on the Grand Canal in Liaocheng prefecture.

[21] In an attempt to gain control over the southern region of Beiping province, Zhu Di launched a new offensive in late February.

[20] In response, the emperor dismissed Qi Tai and Huang Zicheng (on 17 April) and replaced the latter with Ru Chang (茹瑺), who became the leader of the peace party at court along with Li Jinglong.

In July 1401, Sheng Yong attempted to cut the rebel supply lines along the Grand Canal, but was unsuccessful, leaving government troops in northern Shandong in a dire situation.

[23] Based on the counsel of sympathetic Nanjing eunuchs, he chose not to advance through the fortified cities along the Grand Canal, as he had done in previous years.

As a result, the government was forced to withdraw its troops from Beiping province and the city of Dezhou in order to defend Zhili.

[24] With 200,000 troops stationed in Nanjing and its surrounding areas, Zhu Di cautiously approached the heavily fortified city, carefully weighing his options.

[26] On 17 July, Zhu Di ascended the imperial throne as the successor of the Hongwu Emperor and adopted the era name Yongle, which means "perpetual happiness".

[29] This purge was, to some extent, inevitable due to Confucian morality, which did not allow the Jianwen Emperor's staunchest followers to recognize the usurper.

Initially, Zhu Di had no intention of killing him and even made a promise to his mentor Dao Yan that he would not harm him, but after the capture of Nanjing, Fang was paraded and offered a position in the civil service.

When asked if he could be charged with a crime, he replied: Why don't you charge me as a close advisor to the deceased emperor who failed to advise him to deprive you of your princely powers early enough, consequently allowing you to become so fierce and cruel.Qi Tai and other followers of the Jianwen Emperor were executed, along with a large number of their family members, teachers, students, and supporters.