Ming-Đại Việt War (1406–1428)

The Ming-Đại Việt War of 1406–1428 was a conflict between the Ming dynasty of China and Vietnam (known as Đại Việt at the time). The Ming dynasty's objective was to annex Vietnam, and while they initially had some success, the Vietnamese ultimately defended their independence.

The war was sparked by a change in the ruling dynasty in Vietnam. The Ming dynasty did not recognize the legitimacy of the new Hồ dynasty, established in 1400, and demanded the return of the previous Trần dynasty. After their demands were rejected, they responded by invading Vietnam in 1406. The occupied territory was then formed into the province of Jiaozhi, becoming the fourteenth province of the Ming dynasy. Rebellions led by the princes of the Trần dynasty broke out against Chinese rule, but they were ultimately defeated. However, another rebellion led by Lê Lợi in 1418 proved to be too much for the Chinese to suppress. Due to military failures and the heavy cost of war, the Ming army eventually withdrew from Vietnam in 1428. This failure in Vietnam greatly undermined the authority of the Ming dynasty in Southeast Asia.

Background
Đại Việt (Vietnam, specifically the northern region of present-day Vietnam) had been politically independent of China since the 10th century, but was strongly influenced by Chinese culture. The founder of the Ming dynasty, the Hongwu Emperor (r. 1368–1398), considered the cost of expansion greater than the benefit of annexing what he considered "barbaric and backward" territories. Therefore, he included Đại Việt among the territories not to be conquered by his successors.

In the 1390s, the Đại Việt emperors of the Trần dynasty lost power to the minister Lê Quý Ly (1335–1407, from 1400 Hồ Quý Ly). The latter incurred the displeasure of the Ming government when he crossed the border in the north and occupied the Siming district of Guangxi. In the south, Vietnam was repeatedly attacked by the Champa until 1390, when the Cham withdrew after their king fell in battle. In 1400, during civil war in China, Hồ Quý Ly overthrew the Trần dynasty and declared himself emperor of the new Hồ dynasty, changing the name of the state to Đại Ngu. In 1402, he abdicated in favor of his son Hồ Hán Thương, but still held power. In May 1403, he sent a message to the Ming emperor Yongle in Nanjing asking for recognition of his son's rule, on the grounds that the previous dynasty had died out and his son was the nephew of the Trần emperor.

In October 1404, Trần Thiêm Bình, the prince of the overthrown dynasty, arrived in Nanjing and accused Hồ Quý Ly of betraying the rightful ruler. He demanded his own enthronement. The emperor recognized Trần Thiêm Bình's claim in 1405 and invited Hồ Quý Ly to do the same. Hồ Quý Ly had no choice but to confess his crimes and agree to reinstate the Trần dynasty. In the spring of 1406, Trần Thiêm Bình traveled to Vietnam, but on 4 April, shortly after crossing the Sino-Vietnamese border, he was killed by Hồ's Vietnamese forces, along with most of his Chinese escort. When news of the massacre reached Nanjing, the Yongle Emperor, who was already hostile towards the Vietnamese due to their incursions into Champa, Guangxi, and Yunnan, decided to punish them.

Conquest of Vietnam
On 11 May 1406, the Yongle Emperor appointed Zhu Neng, the Duke of Cheng, as the commander of the punitive expedition. He also selected the experienced generals Zhang Fu and Mu Sheng as his deputies. However, before crossing the border, Zhu Neng died in November. As a result, the other two generals had to jointly lead the expedition. With a force of 215,000 men, they launched their attack from Yunnan and Guangxi. The attack was swift and successful, as the Ming troops were able to cross the border on 19 November 1406.

By 20 and 26 January 1407, they had conquered the two capitals of Vietnam—Đông Đô (the Eastern Capital, present-day Hanoi) and Tây Đô (the Western Capital). Hồ Quý Ly and his family retreated to the south, where he organized a new army. However, the war continued for another six months before Hồ Quý Ly and his son were ultimately defeated and captured. They were then taken to Nanjing on 16 June 1407. Zhang Fu gathered the remaining supporters of the Trầns and organized their petition for Vietnam to join the Ming dynasty. The Yongle Emperor, pleased with the easy victory, officially incorporated Vietnam into the Ming dynasty as Jiaozhi Province on 5 July 1407, and began establishing an administration. Zhang Fu successfully crushed the remaining resistance and returned to China with most of the army in 1408.

The rapid conquest of Vietnam in 1406-1407 was a unique event in the history of Sino-Vietnamese conflicts from the 10th to the 20th century. Unlike previous conflicts where Vietnam successfully defended its independence, this time they were unable to do so. Despite careful preparations since 1401, several factors led to the collapse of the Vietnamese defense. On the defenders' side, there was a strong aversion to the new dynasty, low morale, and poor leadership by Hồ Quý Ly. On the other hand, the attackers had capable generals, particularly Zhang Fu, and well-equipped Ming armies with superior firearms and artillery. These weapons were particularly effective against both Vietnamese infantry and elephants, which had been a formidable force in the past. The Ming artillery also played a crucial role in defeating the Vietnamese fleet in river battles.

Ming province
Vietnam became a part of the Ming dynasty as the Jiaozhi Province, on equal footing with the other provinces. The province was divided into 41 sub-prefectures and 208 counties. The province was led by former minister Huang Fu, but his relationship with the Ming court was problematic. An administration was established, consisting of both Chinese and Vietnamese officials. Future officials were educated in Confucian schools taught by Chinese teachers. The population was subject to taxes and labor duties similar to those in China. Colonies of military peasants were also formed, but they were unable to produce enough food to sustain the army stationed in Vietnam. As a result, food, weapons, and equipment had to be imported from China at a high cost. In contrast, Vietnamese experts were sent to China, with 7,600 merchants and craftsmen being sent to Nanjing in 1407. Additionally, the Vietnamese eunuch Nguyễn An played a major role in designing the new Ming capital of Beijing.

After Vietnam became a part of the empire, it still felt like a foreign country to the Chinese. This was evident in the fact that officers were often sent there as a form of punishment, and positions in the civil administration were frequently given to individuals who had failed their civil service exams.

Anti-Ming uprisings
In September 1408, Trần Ngỗi launched an anti-Chinese resistance and declared the restoration of the Trần dynasty in the occupied territory. In response, Mu Sheng was sent from Yunnan to Vietnam to suppress the rebellion. However, the rebels were able to use their knowledge of the environment and gain support from the local inhabitants, successfully defending themselves against Mu Sheng's army. In early 1409, Zhang Fu joined the battle and ultimately defeated and captured Trần Ngỗi in December 1409. He was then recalled to the Mongol border.

However, the fighting did not cease. Trần Quý Khoáng, the nephew of Trần Ngỗi, became the leader of the rebels. The Ming court offered him the rank of provincial governor, but Trần Quý Khoáng refused and the war continued. In early 1411, Zhang Fu returned with reinforcements and defeated the rebels twice, ultimately capturing their capital, Nghệ An (which the Chinese had already lost in 1408). Despite this victory, the fighting persisted. In 1414, Ming troops occupied four prefectures in the south of Vietnam, which had previously been conquered by Champa. However, the Ming's clumsy diplomacy worsened relations with Champa when they rejected her request to return these territories. The turning point in the war came on 30 March 1414, when Trần Quý Khoáng was captured. After his capture, the Vietnamese resistance weakened and in 1416, most of the Ming army was withdrawn.

However, the period of calm was short-lived. The eunuch Ma Ji was sent to Vietnam, where his demands for excessive benefits and levies caused discontent among the local population. By the time Li Bin arrived in February 1417 to replace Zhang Fu, the situation had already begun to deteriorate. In late 1417, the Vietnamese, many of whom were military and civilian officials appointed by the Ming government, rebelled once again. The leader of the rebellion was Lê Lợi, who had previously fought under Trần Quý Khoáng and now declared himself king. Despite losing battles in 1419 and 1420, Lê Lợi turned to guerrilla tactics with the support of the local population. Despite the Ming government's deployment of a large number of troops, they were unable to defeat the Vietnamese. In 1422, Li Bin died and two years later, the Yongle Emperor, the main proponent of the expansionist policy at the Ming court, also died.

Vietnamese victory
In 1424, the Hongxi Emperor dismissed Huang Fu, the governor of the province, and replaced him with Chen Zhi, Earl of Yongchang. According to historians, this decision to remove an experienced and respected governor was a grave mistake. Chen Zhi was unsuccessful in his role, facing challenges with supplies and a lack of knowledge about local conditions. As a result, on 8 May 1426, the Xuande Emperor made the decision to replace him with General Wang Tong. At the same time, the emperor announced to his ministers his intention to end the war in Vietnam. However, there were differing opinions among the ministers. Jian Yi and Xia Yuanji argued for the continuation of the war, while Yang Shiqi and Yang Yong supported the emperor's decision. Ultimately, it was decided to strengthen the army in Vietnam by sending 20,000 soldiers from China and recruiting 30,000 Vietnamese soldiers locally. Additionally, military peasants were mobilized, which further strained the supply situation for the troops.

Now the army of Lê Lợi had strengthened and was not inferior in weaponry to the Ming forces. The army was largely composed of Vietnamese soldiers led by Chinese officers. In the winter, Lê Lợi attacked the Ming garrisons and defeated them in several battles, causing the Ming forces to lose tens of thousands of soldiers. In January 1427, the emperor decided to send strong reinforcements to Vietnam, appointing Liu Sheng as their commander. At the same time, he sent Huang Fu to Vietnam. In April 1427, after a months-long siege, the Vietnamese captured the fortress of Xương Giang. This victory marked a turning point in the war–a shift from guerrilla tactics to a regular army capable of openly confronting the enemy. In September 1427, when Liu Sheng's army of 150,000 men approached the borders, Lê Lợi unexpectedly sent a message to the Ming court, proposing to recognize Trần Cảo, a descendant of the Trần dynasty, as the ruler of Vietnam if the Chinese guaranteed autonomy. A few days later, Liu Sheng's army was defeated and lost 70,000 men. Wang Tong then agreed to Lê Lợi's terms and began to retreat to China. The Ming court only learned of Lê Lợi's offer on 16 November, a month after Liu Sheng's defeat. The ministers were still divided in their opinions on the conflict, but the emperor accepted Lê Lợi's proposal to restore the Trần dynasty and in the first months of 1428, both the military and civilian personnel of the Ming court left Vietnam. However, after his victory, Lê Lợi informed the Chinese envoys that Trần Cảo had died and he would rule alone. He also refused to repatriate the remaining Chinese soldiers and officials.

In 1428 and 1429, the Xuande Emperor demanded the restoration of the Trần dynasty. However, it was not until 1431, after receiving a humble letter from Lê Lợi, that he recognized Lê Lợi's rule over Vietnam de facto. This recognition was given with the title of "administrator of the affairs of Annam", rather than as king. It wasn't until 1436, under the new Emperor Yingzong, that Lê Lợi's successor was officially recognized as the ruler of Vietnam.

The Chinese occupation of Vietnam had a significant impact on the restored Vietnamese state, particularly in the military field. The use of advanced firearms allowed Vietnam to ultimately win the centuries-long war against Champa in the 16th century. Additionally, the twenty years of annexation to the Ming dynasty greatly influenced Vietnamese culture and administrative practices.