Yongle Emperor
The Yongle Emperor, personal name Zhu Di, was the third emperor of the Ming dynasty, reigning from 1402 to 1424. He was the fourth son of the Hongwu Emperor, the founder of the dynasty.
In 1370, Zhu Di was granted the title of Prince of Yan. By 1380, he had relocated to Beijing and was responsible for protecting the northeastern borderlands. In the 1380s and 1390s, he proved himself to be a skilled military leader, gaining popularity among soldiers and achieving success as a statesman. In 1399, he rebelled against his nephew, the Jianwen Emperor, and launched a civil war known as the Jingnan campaign, or the "campaign to clear away disorders". After three years of intense fighting, he emerged victorious and declared himself emperor in 1402.
The reign of the Yongle Emperor is often described as the "second founding" of the Ming dynasty, reflecting the major changes he introduced to his father's political system. In 1403, he elevated Beijing to the status of a second capital, diminishing the importance of Nanjing. Construction of the new capital between 1407 and 1420 employed hundreds of thousands of workers, with the Imperial City and the Forbidden City forming its core. The Emperor also supervised the reconstruction of the Grand Canal, essential for supplying Beijing and the northern armies.
The Emperor strongly supported both Confucianism and Buddhism and sponsored the compilation of the vast Yongle Encyclopedia, employing around two thousand scholars. This work surpassed all earlier encyclopedias, including the Four Great Books of Song from the 11th century. He also ordered Neo-Confucian texts to be systematized and used as textbooks for training officials. The civil service examinations, held every three years, produced qualified candidates for government service. Although known for imposing harsh punishments on failure, the Emperor readily rewarded capable officials. Unlike his father, he avoided frequent purges, resulting in longer ministerial tenures and a more professional, stable administration. The Emperor often ruled "from horseback", traveling between the two capitals in a manner reminiscent of the Yuan emperors. This approach, however, was criticized by officials who feared the growing influence of eunuchs and military elites, whose power depended on imperial favor.
The Emperor made considerable efforts to reinforce the empire's hegemonic position in East Asia through an active foreign policy. Diplomatic missions and military expeditions were dispatched to "all four corners of the world", reaching regions both near and distant, including Manchuria, Korea, Japan, the Philippines, and the Timurid Empire in Central Asia. Zheng He's maritime expeditions extended even further, reaching the shores of Southeast Asia, India, Persia, and East Africa. The Mongols remained the most serious security threat to the empire. They were divided into three main groups: the southeastern Uriankhai, who were largely loyal, and the eastern Mongols and western Oirats, who posed ongoing challenges. The Ming court alternately supported and confronted these groups. The Emperor personally led five campaigns into Mongolia, and his decision to transfer the government from Nanjing to Beijing was driven largely by the need to closely monitor the unstable northern frontier.
The Yongle Emperor was a skilled military leader and placed great emphasis on the strength of his army, but his wars were ultimately unsuccessful. The war in Jiaozhi, which began with an invasion in 1407, lasted until the end of his reign. Four years after his death, the Ming army was forced to retreat back to China. Despite his efforts, the campaigns against the Mongols did not significantly alter the balance of power or ensure the security of the northern border.
Early years
Childhood
Zhu Di, the future Yongle Emperor, was born on 2 May 1360 as the fourth son of Zhu Yuanzhang. At the time, Zhu Yuanzhang was based in Nanjing and was a prominent leader in the Red Turban Rebellion, an uprising against the Mongol-led Yuan dynasty that controlled China. The rebellion aimed to restore Han Chinese rule after decades of Mongol domination. In the 1360s, Zhu Yuanzhang conquered China, established the Ming dynasty, and declared himself emperor. He is commonly known by his era name as the Hongwu Emperor.After taking the throne, Zhu Di claimed to be the son of Zhu Yuanzhang's primary wife, Lady Ma, who had been empress since 1368, but other sources suggest that his real mother was a concubine of the Hongwu Emperor with the title Consort Gong, who was either Mongolian or possibly Korean. Zhu Di attempted to present himself as the Hongwu Emperor's legitimate successor by declaring himself and the Hongwu Emperor's fifth son, Zhu Su, as the only sons of Empress Ma in the 1403 edition of the official Veritable Records of Taizu. This was preposterous, as it was unlikely that a son of the Empress would not be named as successor during the Hongwu Emperor's lifetime. Therefore, in the later version of 1418, all of the Hongwu Emperor's eldest five sons were recognized as her children.
Zhu Di spent his childhood in Nanjing, where he and his siblings were raised with a strong emphasis on discipline and modesty. Out of all his siblings, he had a special fondness for Princess Ningguo, Zhu Fu and Zhu Su. Zhu Su was only 15 months younger than Zhu Di, and they became close friends despite their contrasting personalities. While Zhu Di enjoyed activities such as archery and horseback riding, Zhu Su preferred studying literature and tending to plants.
The Hongwu Emperor took great care in the education of his sons, appointing leading scholars of the empire as their tutors. Initially, Song Lian was appointed as the teacher for the heir to the throne, and also gave lectures to the other princes. Song Lian's successor, Kong Keren, who taught the Emperor's sons philosophy and ethics, had a significant influence on Zhu Di. His favorite subject was the history of the Han dynasty, particularly Emperors Gaozu and Wu of Han, but he often referenced examples from the life of Qin Shi Huang in his decrees as emperor.
Youth
On 22 April 1370, the Emperor's sons, with the exception of the heir to the throne, were granted princely titles. Zhu Di was given the title of Prince of Yan, with his fief located in Beiping. During the Mongol-led Yuan dynasty, Beiping served as the capital of China. After being conquered by the Ming dynasty in 1368, it became a crucial stronghold for the troops guarding the northern border and was also designated as the capital of the province with the same name.At that time, Zhu Di was given his own household, with advisor Hua Yunlong and tutor Gao Xian at its head. Gao Xian spent the next four to five years lecturing him on Confucian classics, history, agriculture, and irrigation. He also trained the prince in poetry and prose writing, and explained the rules of governance and the selection of subordinates. After Hua's death and Gao's dismissal, Fei Yu, Qiu Guang, Wang Wuban, and Zhu Fu took over Zhu Di's education. Despite receiving a comprehensive education from esteemed teachers, Zhu Di's true passion always lay in military pursuits rather than scholarly pursuits and palace discussions.
File:仁孝文皇后徐氏（明太宗（成祖））.jpg|thumb|upright=0.8|Portrait of Lady Xu, Zhu Di's wife, as empress. National Palace Museum, Taipei, Taiwan
In early 1376, Zhu Di married Lady Xu, the daughter of Xu Da, who was ranked first among the early Ming generals. She was two years younger than him. Lady Xu was known for her intelligence, decisiveness, and energy. Their first son, Zhu Gaochi, was born on 16 August 1378. The couple had two more sons, Zhu Gaoxu and Zhu Gaosui.
A few weeks after his wedding, Zhu Di traveled to Fengyang, where he spent seven months in military training alongside his elder brothers Zhu Shuang and Zhu Gang. Two years later, he returned to Fengyang with his younger brothers Zhu Su, Zhu Zhen, and Zhu Fu, remaining there for another two years. During this period, he not only trained in command and combat but also learned military logistics, including the acquisition and transport of supplies. It was at this time that his organizational abilities began to take shape, skills he later applied effectively in warfare. He also disguised himself as an ordinary soldier to experience the lives of common people, and later recalled his years in Fengyang as the happiest of his life.
In 1376, Li Wenzhong, the nephew and adopted son of the Hongwu Emperor and the official responsible for northern defense, was tasked with preparing Zhu Di's palace in Beiping. Using former Yuan imperial palaces, he provided Zhu Di with a residence that was larger and more heavily fortified than those of his brothers, many of whom lived in converted temples or local government buildings. Li Wenzhong also strengthened the city's defenses, a decision that later proved significant during the civil war when his son, Li Jinglong, failed to capture Beiping in 1399.
Prince of Yan in Beiping
In April 1380, at the age of twenty, Zhu Di moved to Beiping, where he encountered strong Mongolian cultural influences that the government sought to suppress by banning Mongolian customs, clothing, and names. The city had largely recovered from the famines and wars of the 1350s and 1360s and was undergoing renewed growth. It housed hundreds of thousands of soldiers, along with provincial officials, artisans, and laborers from across the empire. The primary challenge for local authorities was ensuring an adequate food supply. To address this, peasants were resettled in the north, soldiers and convicts were assigned to farm the land, and merchants were granted salt-trading licenses in exchange for transporting grain to the region. The government also shipped food supplies directly to the city.Zhu Di's interest in the military was put into practice when he personally trained his own guard. He used his detachments as a means of balancing the power of the provincial commander, who was unable to mobilize troops without authorization from the Emperor and approval from the prince. Meanwhile, Zhu Di had the freedom to train and deploy his own guard. In 1381, he had his first experience in the field when he joined his father-in-law Xu Da's campaign against the Mongols, led by Nayur Buqa.
In the 1380s, Zhu Di served in border defense under the leadership of Xu Da. After Xu Da died in 1385, his deputy Fu Youde took over leadership. In 1387, Zhu Di participated in a successful attack on the Mongols in Liaodong, led by Feng Sheng. The following year, a Ming army led by Lan Yu made a foray into eastern Mongolia and defeated the Mongol khan Tögüs Temür, capturing many prisoners and horses, but both generals were accused of mistreating captives and misappropriating booty, which the prince reported to the Emperor.
In January 1390, the Emperor entrusted his sons with independent command for the first time. He gave the princes of Jin, Yan, and Qi the task of leading a punitive expedition against the Mongol commanders Nayur Buqa and Alu Temür, who were threatening Shanxi and Gansu. Zhu Di demonstrated excellent command skills when he defeated and captured both Mongol commanders in battle. They then served under him with their troops. The Emperor appreciated Zhu Di's success, which contrasted with the hesitancy of Zhu Gang. Zhu Di continued to lead armies into battle against the Mongols repeatedly and with great success.
In 1392, the Emperor's eldest son and heir, Zhu Biao, died, prompting court discussions over the succession. The principle of primogeniture, supported by Hanlin Academy scholars and senior officials, ultimately prevailed, and Zhu Biao's son, Zhu Yunwen, was named heir. Generals Feng Sheng, Fu Youde, and Lan Yu, who were related to the successor, were appointed as his tutors. After a recommendation by Zhu Di, the Hongwu Emperor began to suspect these generals of treason. Zhu Di had a poor relationship with Lan, and according to historian Wang Shizhen, he played a role in Lan's execution in March 1393. The other two generals died under unclear circumstances around 1394–1395. They were subsequently replaced by princes. In 1393, Zhu Gang was given command of all troops in Shanxi province, while Zhu Di was placed in command of Beiping province. Zhu Shuang, Prince of Qin, was in charge of Shaanxi, but died in 1395.
The Hongwu Emperor, who was deeply affected by the death of his two eldest sons and the strained relations between his remaining sons and his heir, made the decision to revise the rules governing the imperial family for the fourth time. The new edition significantly limited the rights of the princes. These changes had little impact on Zhu Di's status as they did not affect his main area of expertise—the military. Furthermore, Zhu Di was cautious not to give any reason for criticism. For example, he did not object to the execution of his generals Nayur Buqa and Alu Temür, who were accused of treason. He also exercised caution in diplomatic relations, such as when he welcomed Korean delegations passing through Beiping, to avoid any indication of disrespect towards the Emperor's authority.
Out of the six princes responsible for guarding the northern border, Zhu Di was the second oldest but also the most capable. He had operated in a vast territory, stretching from Liaodong to the bend of the Yellow River. He was not afraid to take risks, as demonstrated by his defeat of the Mongols led by Polin Temür at Daning in the summer of 1396. He also went on a raid with his brother Zhu Gang several hundred kilometers north of the Great Wall, which earned them a sharp reprimand from their father. In April 1398, Zhu Gang died, leaving Zhu Di as the undisputed leader of the northern border defense. Two months later, Zhu Di's father also died.