How many Nguyen Mong soldiers lost their lives in Dai Viet?

With the ambition to expand its territory to the south, the Nguyen Mong empire raised an army to attack Dai Viet three times in the 13th century.

In 1254, the Mongol Empire just finished conquering the country of Dali, sent messengers to Dai Viet to ask for a loan to continue fighting the Southern Song (China). The Tran king did not agree and ordered the imprisoning of the Mongol messenger. The Mongol emperor heard the news and immediately sent his army to prepare to conquer Dai Viet.

In January 1258, the Mongols moved to Dai Ly and from there invaded Dai Viet. King Tran Thai Tong and Crown Prince Tran Hoang sent troops to meet the enemy at Binh Le Nguyen (Vinh Phuc), but the Mongols soon prevailed and won the next battle at Phu Lo (Soc Son, Hanoi today).

Knowing that confronting a strong enemy was impossible, King Tran withdrew his army and evacuated the people. Thang Long Citadel was placed in the position of “a garden without an empty house”, causing the Mongols to fall but gradually fell into terrible hunger.

When the enemy’s position was weak and morale was reduced, King Tran Thai Tong led his army to attack Dong Bo Dau (Hanoi) and destroyed a large amount of enemy strength. The Mongols ran, and on the way back, they were ambushed and destroyed a lot. The Persian historian Said ud Zin said that the Mongol army had about 30,000 and 20,000 Dali troops, totaling over 50,000 to attack Dai Viet. After the battle, the Mongols recorded only 5,000 men remaining.

More than 20 years later, the Mongols defeated the Song Dynasty, establishing the Yuan Empire, consisting of present-day Mongolia and China. In 1285, the Yuan Emperor Kublai (grandson of Genghis Khan) ordered a second attack on Dai Viet under the pretext of borrowing a way to destroy Champa but was refused.

This time, the initial position also quickly tilted towards Mongolia. Dai Viet troops were defeated at Lang Son, Son Dong, Van Kiep and Duong Rivers. Within 3 weeks of pulling troops across the northern border, the Mongols captured Thang Long citadel.

The Mongols attacked strongly on all fronts, forcing the Tran dynasty to retreat to Quang Ninh. Here, the Tran soldiers and local militiamen carried out the resistance war, causing the Mongols to gradually fall into starvation.

After two months of “hiding for the time”, Dai Viet troops counterattacked at Ham Tu gate (Hung Yen), Chuong Duong wharf (Thuong Tin, Hanoi) and liberated Thang Long citadel. When the Mongols withdrew to the north, they were ambushed at Cau River, while the southern army was attacked and completely destroyed in Tay Ket (Hung Yen).

Dai Viet History Records Toan Thu recorded that the Nguyen army fought against Dai Viet for the second time with 50,000 VND and when he withdrew, it was only 50,000. Quan Nguyen brought a large amount of logistics, including many people who raised the army. However, some Vietnamese scholars later said that the number of Mongols who invaded Dai Viet was about 30,000, and the number that escaped to the country could be more than 50,000. This hypothesis is consistent with the time when the Yuan army was ordered to prepare (only 2 months later) for the 3rd invasion.

The third war took place from December 1287 to April 1288. The Yuan army followed three wings from Yunnan, Guangxi and Guangdong (by sea) to flood Dai Viet with the support of food boats to ensure “self-sufficiency”, to deal with the army’s scorched earth tactics. Vietnamese. However, this convoy was scuttled a lot by Dai Viet General Tran Khanh Du. The rest met storms or got lost at sea.

Soldiers of the Tran Dynasty for the 3rd time applied the strategy of fighting to hold back, withdrawing most of their forces to Do Son (Hai Phong). After that, the troops attacked Van Kiep base and attacked the Nguyen navy, especially the battle of Van Don completely cut off the food of the Nguyen army. Due to the raging famine, the army was exhausted, the Nguyen army abandoned Thang Long citadel, withdrew to Van Kiep and then pulled their own troops back to the country. On the way to withdraw, the navy was completely annihilated at the battle of Bach Dang, the army was also beaten down when passing Bac Giang and Lang Son.

Dai Viet Su Ky Toan Thu recorded the number of troops for the third time as 50,000, while Kham Dinh Viet Su Thong Giam Cuong Muc said that was too much. According to the history of Vietnam, the number of Nguyen troops who fought Dai Viet for the third time was about 30,000, close to the number in the An Nam Chi strategy as well as the judgments of some later historians. According to an article by historian Dang Hung, the third time the Yuan army lost about 30,000 troops.

A total of three times, the Mongols brought in from about 650,000 to 1 million troops (plus according to the different documents mentioned above). The first time at least with the number of troops “exploring” 50,000 people. Kublai Khan seems to subjectively think that only 50,000 troops are enough to annex Dai Viet with 4 million people, but his calculation is wrong.

When the soldiers increased to 10 times this number in the second and prepared enough provisions for the third, the outcome was still a disaster. Most of the Mongols died in Dai Viet.

According to Dai Viet Su Ky Toan Thu and historian Dang Hung, in total, Nguyen Mong lost about 80,000 troops after 3 times sending troops to fight Dai Viet. According to other historical records, Nguyen Mong also lost an estimated 40-50 thousand troops.

According to Dao Duy Anh’s book The History of Vietnam from Origins to the 19th Century, there were 3 main reasons for the defeat of the Mongols. First of all, to deal with the tactic of plundering food, the Tran Dynasty used the “empty garden” strategy to weaken the enemy. For the third time, although the Nguyen troops had learned to carry food, Dai Viet fought the battle of Van Don, completely paralyzing the enemy’s logistics.

The second reason is that people from the north are not compatible with water and earth. In the end, the Yuan army consisted mainly of multi-racial soldiers, made up of countries conquered by this empire. Therefore, the fighting mentality of this army was not good and easily disintegrated.

In addition, the prominent leaders of Dai Viet such as Hung Dao Vuong Tran Quoc Tuan often chose the terrain of the riverbank or the jungle to fight, suppressing the strength of the Mongol cavalry, using tactics to take more or less enemies. , made resounding victories.