2.38. History of the Mongols: Invasions of Vietnam

<p><em><span style="font-weight: 400;">"In the West there is a province called Kafje-Guh, in which there are forests and other places of difficult access. It adjoins Qara-Jang and parts of India and the coast. There are two towns there, Lochak and Hainam and it has its own ruler, who is in rebellion against [Kublai Khaan]. Toghan, the son of the [Khaan], who is stationed with an army in Lukin-fu in the [south of China], is defending [China] and also keeping an eye on those rebels. On one occasion, he penetrated with an army to those towns on the coast, captured them, and sat for a week upon the throne there. Then all at once their army sprang out from ambush in the sea[shore], the forest, and the mountains and attacked Toghan's army while they were busy plundering. Toghan got away safely and is still in the Lukin-fu area."</span></em></p> <p> </p> <p><span style="font-weight: 400;">   </span> <span style="font-weight: 400;">So the Ilkhanid historian and vizier Rashid al-Din, writing in the first years of the 1300s, describes events less than twenty years prior but very far away. Rashid al-Din transcribed a very brief, but recognizable sketch, of the Mongol invasions of Vietnam in the 1280s. Having covered for you the first half of Kublai's reign up until the end of the 1270s and his conquest of China, we will now take you to the beginnings of his failures. Back in July we already presented the Mongol invasions of Japan in 1274 and 1281, so now we'll turn our gaze southwards, to the efforts to extend Mongol suzerainty over the kingdoms of what is now Vietnam. I'm your host David, and this is Kings and Generals: Ages of Conquest.</span></p> <p> </p> <p><span style="font-weight: 400;">   </span> <span style="font-weight: 400;">Before we discuss the military operations, it's useful to set the scene and establish Vietnam's 13th century status. As has been so often over this series, for context we must go back to the fall of China's Tang Dynasty in 907. For roughly a thousand years, starting from the Han Dynasty in 111 BCE, the northern half of what is now Vietnam was under Chinese dominion, broken up by a few decades of revolts and brief independence here and there. Of course, the Chinese Dynasties were not dominating a 'Vietnam' in any modern sense. Rather, they were exerting control or tributary relationships with the Viet, or Kinh, peoples around the Red River, or Hong River, Delta. This delta is usually described as the cradle of Vietnamese civilization, the most densely populated and fertile part of the country even today. Vietnam's capital, Hanoi, sits in this region. The long period  of Chinese rule and influence left an undeniable mark upon Vietnamese conceptions of state, and every succeeding Viet dynasty has born obvious echoes of it.</span></p> <p> </p> <p><span style="font-weight: 400;">   </span> <span style="font-weight: 400;">With the collapse of the Tang in 907, the Chinese presence in the north of Vietnam weakened, and local groups began to exert independence. Some of the Tang's successors in Southern China invaded and briefly brought the Red River Delta back under Chinese rule. But by the middle of the tenth century, the first fully independent Vietnamese Dynasty in centuries, the Ngô Dynasty, was established… and collapsed into feuding warlords by 965. It was not until the Lý Dynasty, founded in 1009, was stability reached. Under the Lý Emperors- though only Kings, if you asked the Chinese- the recognizable aspects of medieval northern Vietnam were built. The capital was moved to Thăng Long, modern day Hanoi. Buddhism was adopted as the state religion, and in 1054 a new emperor declared a new name for their state;</span> <em><span style="font-weight: 400;">Đại Việt,</span></em><span style="font-weight: 400;">, meaning 'great Viet,' by which we most commonly know the medieval and early modern state. Administrative and military reforms made it the most stable and powerful Vietnamese kingdom yet, and the state expanded both north and south. Agricultural expansion and land reclamation fueled population growth and a steady Viet colonization southwards.</span></p> <p> </p> <p><span style="font-weight: 400;">   </span> <span style="font-weight: 400;">Good times for the Lý Kings did not last. By the start of the thirteenth century their rule had weakened, local warlords exerted their independence and the monarchs were generally inept with few heirs. In a series of political alliances and marriages, the Trần family gathered power and began to try to force the Lý Kings to be their puppets. Warfare broke out. The Lý Kings maintaned the throne, but with the Trầns the power behind it. The final ailing Lý King abdicated the throne in 1224 with only two daughters. His 7 year old daughter, Lý Chiêu Thánh, was enthroned as the only queen-regent in Vietnam's history. Throught the machinations of the Trần "mayor of the palace,"  Trần Thủ Độ married the young queen to his nephew, Trần Cảnh. The queen soon abdicated the throne, making Trần Cảnh the reigning monarch- the first ruler of Vietnam's prestigious Trần Dynasty, known by his temple name Thái Tông, the Vietnamese rendition of that classic Chinese temple name, Taizong. His father was posthumously made Taizu, and the scheming uncle Thủ Độ became the chancellor and the major powerbroker within Đại Việt until his death in 1264.</span></p> <p> </p> <p><span style="font-weight: 400;">   </span> <span style="font-weight: 400;">The powerful new Trần Dynasty of Đại Việt centralized power and continued the expansion begun the Lý  Dynasty. Further reclamation efforts and dykes to control the flooding of the Red River continued to increase the agricultrual production of the north. Adminsitration, territories, taxes, the army, the law code, all were reorganized under the Trần. Confucianism influenced the government but did not replace Buddhism, and Chinese was the official language of the court. Relations were stabilized with their most important neighbours; the Song Dynasty to the northeast, to which Đại Việt paid tribute and nominal allegiance in exchange for expensive gifts and lucrative trade; to the northwest, trade flowed with the Dali Kings in Yunnan; to the south, a cordial period began with the Chams. </span></p> <p> </p> <p><span style="font-weight: 400;">The Chams are a part of the far flung Austronesian people, inhabiting central and southern Vietnam for millenia. For most of their history they were a collection of small, competing Hindu and Muslim kingdoms, but in the 12th century entered a new period of unity in the face of an invasion by the Khmer Empire of Cambodia, the builders of the famed Angkor Wat. United under a 'king of kings,' the Chams repulsed both the Khmer and Đại Việt when it attempted to take advantage of perceived Cham weakness. Though not unified or centralized in the manner of Đại Việt, from the mid-12th century onwards there was a King of Kings based out of Vijaya who wielded more influence over the other Cham kings and princes- the kingdom of Champa, as it's sometimes called. And hence, by the 13th century we can say that Vietnam was divided into two states; Đại Việt in the north, ruled by the Trần Dynasy and known as Annam to the Chinese, and Champa in the south. You can get your references to twentieth century North and South Vietnam out of the way now.</span></p> <p> </p> <p><span style="font-weight: 400;"> Đại Việt was the first of the two to encounter Mongol armies in the 1250s. As we've discussed a few times before, in 1253, on the orders of his brother the Grand Khan Mongke, prince Kublai marched into Yunnan and conquered the Dali Kingdom. Though Kublai quickly returned north, his general Uriyangqadai stayed in the region and continued to subdue the local peoples. Uriyangqadai, the son of the illustrious Sube'edei, led a series of wide ranging campaigns across Yunnan, the edges of Tibet to the small kingdoms on the western edge of the Song Dynasty. In this process, Uriyangqadai came right to the northern border of Đại Việt. At this point Mongol imperial ideology was well entrenched:</span> <em><span style="font-weight: 400;">of course</span></em> <span style="font-weight: 400;">Đại Việt would become subject to the Grand Khan. The more immediate strategic concern though was to prevent the Trần kings offering any sort of support to the Song Dynasty, against which Mongke was planning a massive assault upon for 1258. With Đại Việt's trade and tribute contacts with the Song, the Mongols were not willing to allow a possible enemy in their rear. With his envoys to the Trần court at Thăng Long illicting no response, in the winter of 1257 Uriyangqadai and his son, Aju, led the army over the border, some 10-30,000 men, Mongols supported by locally raised troops from Yunnan.</span></p> <p> </p> <p><span style="font-weight: 400;">Splitting his forces into two, Uriyangqdai ordered the vanguard to cross the Thao River, north of Thăng Long, but not engage the Việt forces; Uriyangqadai knew of the river fleets used by Đại Việt, and desired to draw them into an ambush and thus neutralize their mobility. The vanguard commander did not listen and immediately engaged with the enemy, and a frustrated Uriyangqadai then advanced to support him. Despite the insubordination and the Vietnamese fielding war elephants, the Mongols had the better of the battle; Aju is said to have ordered archers to shoot into the eyes of the elephants. However, a defiant rear guard allowed the Trần leadership to escape the battle on the ships, and the always strict Uriyangqadai ensured the foolish vanguard commander paid for this with his life.</span></p> <p> </p> <p><span style="font-weight: 400;">The Trần forces again attempted to stop the Mongol advance, occuping a bank of the Phù Lỗ river at the start of 1258 and cutting down the bridge. The Mongols cleverly found a ford; shooting arrows into the sky, when they fell and disappeared -meaning they had sunk into the mud- that indicated an area shallow enough to cross. They met and routed the Trần army, and now they rushed onto the capital, Thăng Long- only to find it abandoned. The Trần King, government and most of its population had evacuated before the Mongol arrival, taking most of the foodstuffs with them.</span></p> <p> </p> <p><span style="font-weight: 400;">Vietnamese and the Chinese sources differ on the precise details of what followed, but generally it can be said that Uriyangqadai withdrew, and was harassed by local forces as went, and the Trần King offered tribute to keep the Mongols at bay. It may have been that the heat, humidity and tropical disease wreaked havoc on Mongolian men, bows and horses and he wanted out of there as quickly as possible, only escaping with heavy losses. It may have been that due to the timetable Mongke had set for the assault on the Song, Uriyangqadai simply did not have time to stay in Đại Việt any longer. Indeed, upon his return to Mongol occupied Yunnan, he was almost immediately leading forces into the Song Dynasty's southwestern border.</span></p> <p> </p> <p><span style="font-weight: 400;">The Trần Kings now sent tribute to the Mongols, expecting it would be a continuation of the relationship they had had with the Song: tribute once every three years, a nominal submission to keep the peace. For almost two decades, this was essentially what followed, as the Mongols were too preoccupied with the succession struggle after Mongke's death and Kublai's ensuing war with the Song Dynasty to press the matter further. Likewise, Champa began to send tribute to the Khan. With the Song still a buffer between them, the kingdoms of Vietnam felt some security from the Mongols.</span></p> <p> </p> <p><span style="font-weight: 400;">   </span> <span style="font-weight: 400;">However, Kublai began asking for both monarchs to submit to him in person and confirm their allegiance, which both put off in favour of continued tribute missions. Other demands had to be met as Mongol vassals, such as censuses, allowing</span> <em><span style="font-weight: 400;">daruqachi</span></em> <span style="font-weight: 400;">to be posted in their cities and demands for labour and materials- all were requirments neither kingdom had yet to meet.  The end of Song resistance at Yaishan by 1279 to Kublai's Yuan Empire removed  the buffer between them, and now the excuses of the Trần and Cham kings was far less acceptable, as was their housing of fleeing Song officials. In 1280 Kublai demanded that if the Trần king could not come in person, then he must send a massive golden likeness of himself with pearls for eyes, as well as increased amounts of tributes, as well as demanding the kingdom's most skilled doctors and artisans, most virtuous scholars and most beautiful women every three years. The Great Khan's demands grew ever greater, the intention clear: the submission of Đại Việt and Champa</span> <em><span style="font-weight: 400;">must</span></em> <span style="font-weight: 400;">be total.</span></p> <p> </p> <p><span style="font-weight: 400;">Kublai's eyes were also going further afield. Dreaming of completing the conquest of the world, the fall of the Song, the greatest single independent power not subject to the Mongols, seemed to open up access to valuable maritime trade routes.  It has been speculated that Kublai saw Champa as key to controlling the south-east Asian trade, essentially a landing strip jutting out into the trade routes darting from India, Indonesia and China. After years of perceived insubordination, once the Chams imprisoned Yuan envoys in 1282, Kublai had his pretext for war and a chance to seize the sea trade. Striking at Champa first had the added benefit of putting Đại Việt in a vice grip between Yuan China and an occupied Champa, and hopefully bring it to heel as well. Having overcome the formidable Song Dynasty, the often politically fragmented Champa would have seemed an easy target in comparison. Officials in Guangxi province had sent encouraging messages to the court, saying less than 3,000 men would be needed to overrun the Chams. After the failure of the second invasion of Japan in 1281, Kublai was also hungry for a quick and easy victory. Though the 1270s had been successful, they had worn Kublai out; by the 1280s, he was no longer the patient man he had been in the 1250s, planning out every detail of the Dali campaign with his experienced generals and advisers. His most loyal and critical advisers had died over the 1270s, and Kublai had outlived the most veteran commanders. Having come to expect total victory regardless, Kublai now demanded it immediately.</span></p> <p> </p> <p><span style="font-weight: 400;">   </span> <span style="font-weight: 400;">In December 1282, Sogetu, a hero of the final war against the Song Dynasty and governor of Fujian, departed with 5,000 men drawn from former Song territory aboard a hundred transport ships, arriving near the Cham capital of Vijaya in February 1283. After brief resistance, Vijaya fell to Sogetu, who found that the Cham leadership, its King Indravarman V and Prince Harijit, had fled into the mountains. After wasting a month in fruitless negotiation with Cham envoys, once Indravarman executed his envoys, in March 1283 Sogetu set out on the attack.  In the jungle his men were ambushed and driven back, and Sogetu retreated to the coast where he cleared land to plant rice to feed his men. There, he sent envoys to the Khmer Empire (who were detained) and sent messages to the Yuan court for aid. </span></p> <p> </p> <p><span style="font-weight: 400;">   </span> <span style="font-weight: 400;">Initially, the court's response was slow, still planning for a third invasion of Japan. Ariq Khaya, the Uighur commander who had helped crush the last of Song resistance, was ordered to raise thousands of Jurchen, Northern Chinese and former Song troops to aid Sogetu, but failed to do so. It was not until March 1284, after plans for the third Japanese invasion were finally abandoned, when an army of 20,000 was dispatched to aid Sogetu. Setting out by sea and delayed by a brief mutiny, they arrived the next month to link up with a campaigning Sogetu, who had begun sacking Cham cities along the coast. The Cham King Indravarman sent word he was willing to submit, but would be unable to offer tribute due to the plundering. Such concerns did not really bother the Mongols.</span></p> <p> </p> <p><span style="font-weight: 400;">   </span> <span style="font-weight: 400;">By August 1284 the Yuan court had received maps showing the land routes through Đại Việt to Champa, and it was declared that Kublai's eleventh son Toghon would lead a force overland to assist Sogetu. Đại Việt was ordered to help supply this army, but they refused: it was immediately apparent in the Trần court that this was almost certainly a pretext for a Yuan conquest of Đại Việt. At that time, the reigning Trần King was Trần Khâm, temple name Trần Nhân Tông. His father, the previous king Trần Thánh Tông, was still alive: the Vietnamese had a similar institution to the Japanese, wherein the previous monarch would 'retire,' abdicating the throne for their heir and as 'emperor-emeritus,' tutor their successor while stepping out of all that strict court protocol. So it was in 1284 that the 15th century chronicle the</span> <em><span style="font-weight: 400;">Complete Book of the Historical Records of Đại Việt</span></em><span style="font-weight: 400;">, records a famous episode. The 'emperor-emeritus' Trần Thánh Tông, once it was apparent that the Mongol attack was forthcoming, summoned elders and advisers from across Đại Việt to discuss the best course of action and strategy. Supposedly, they all shouted in unison, "Fight!"</span></p> <p> </p> <p><span style="font-weight: 400;">So the Trầns began to prepare for the assault, readying officers and men. Of these, one man is the most famous for his preparations, Trần Quốc Tuấn, though you may know him better by his later title, Prince Hưng Đạo. Part of Hưng Đạo's long standing popularity in Vietnamese history was his character, worth a small digression. Hưng Đạo's rise to prominence was an unexpected thing. He was the nephew of the first Trần King, the son of his rebellious older brother. While his father died disgraced and as a traitor, Hưng Đạo made himself a shining beacon of loyalty and filial piety- two very good traits to have if you want to have Confucian inspired historians write nice things about you. Hưng Đạo actively made himself appear the most loyal of all the Trần King's servants, perhaps to overcompensate for his father's actions. His charisma, natural talent and skill made his life an exemplary subject for chroniclers to fawn over,  with one notable exception: when he was around 20 years old, Hưng Đạo had an affair with an imperial princess already engaged to another man. It was a scandal resolved by marrying the two, but was nonetheless an embarrassment. When it became apparent that war was coming, Hưng Đạo marked himself out by preparing and training men and officers, before taking a leading role in the strategy himself.</span></p> <p> </p> <p><span style="font-weight: 400;"> In January 1285, Prince Toghon and Ariq Khaya led some eight tumens over the border from Yunnan into Đại Việt. He had with him an ousted member of the Trần royal family, Trần Ích Tầc, who the Yuan had declared the new King of Đại Việt and were going to place onto the throne. In addition, another column came further west, led by Nasir ad-Din, the Khwarezmian appointed by the Mongols to govern Yunnan; he was the son of the first Mongol appointed governor of the province, a skilled figure named Sayyid Ajall. The forces sent against Toghon, Ariq Khaya and Nasir ad-Din were quickly overcome, and captured ships allowed them to cross the Phu-luong River in February.  Meanwhile, Sogetu was marching north, a great pincer movement on Đại Việt. Prince Hưng Đạo divided his forces to try and prevent Sogetu from linking up with Toghon, but Sogetu overwhelmed them, capturing 400 renegade Song officials. By the time Sogetu linked up with Toghon, the Prince had constructed a full river fleet and placed them under the command of Omar, one of the Yuan's top naval commanders and Nasir ad-Din's son. Together, they undertook a full offensive against Đại Việt, Omar driving the King out to sea while Toghon and Sogetu captured the capital of Thăng Long. Armies sent against them were annhilated and many Trần generals defected to the Yuan forces.</span></p> <p> </p> <p><span style="font-weight: 400;">   </span> <span style="font-weight: 400;">With Thăng Long's seizure, the Yuan experienced their final success of this campaign. Again, Thăng Long had been skilfully evacuated to deny the Mongols access to supplies or the royal family, thus preventing the city's occupation from being a true strategic gain. In Thăng Long, Yuan forces and supply lines were overextended, running low on food while heat and disease took their toll. In June one of the Yuan commanders, Li Heng, was killed by poisoned arrows and his force decimated by ambushes. A former Song Dynasty officer and his entourage, fighting alongside the Vietnamese, donned their old Song style uniforms and armours, which panicked  the Yuan detachments thinking they were now facing long-lost Song reinforcment! The fallen Vietnamese were found to have tattooed "kill the Tatars!" on their own bodies, angering, frustrating and frightening the Yuan forces- many of whom, it should be noted, were not Tatars but conscripted Chinese and others who would be forced to share their fate. All bodies with such tatoos were ordered to be decapitated. Toghon, seeing their position was untenable as morale crumbled, decided to call a full retreat back to Yuan territory. So swiftly was this done that Toghon failed to inform Sogetu of the retreat, who suddenly realized he was left isolated deep in enemy territory.  Hurriedly he forced his way north, but the Vietnamese harried him. Sogetu was captured and killed in battle, and the remainder of his force was largely surrounded and destroyed at Ssu-ming on the Yuan border.</span></p> <p> </p> <p><span style="font-weight: 400;">   </span> <span style="font-weight: 400;">This was a disastrous end to the campaign. The Mongols had suffered reversals, loss of commanders and had to turn back from campaigns before. Battles had been lost of course, but major defeats like the Japan invasions could be explained away as the interventions of nature and the heavens. But the Vietnam campaign was a direct military fiasco, one of Kublai's own sons failing to deliver victory.  Kublai was so furious he refused to allow Toghon back to the capital. Frustrated by failures and his mind increasingly clouded by drink and depression, Kublai ordered a third invasion of Đại Việt. Special care was taken for this invasion. The Trần pretender Trần Ích Tầc was once again to be promoted, to hopefully encourage dissension, and great effort was taken to prevent the logistical issues of the previous campaign. Supply ships were ordered from all along the southern Chinese coast to ferry troops and provide the food necessary for the great army being assembled: 70,000 Mongol, Jurchen and Northern Chinese, 6,000 troops from Yunnan, 1,000 former Song soldiers, 6,000 local troops from Guangxi and 17,000 Loi people from the island of Hainan, for a total of 100,000 men not including the crews of the 500 warships and transports. Toghon was placed in overall command again, his final chance to redeem himself before his aging father. </span></p> <p> </p> <p><span style="font-weight: 400;">   </span> <span style="font-weight: 400;">While it is easy to focus on the Yuan losses, it must not be thought it was an easy experience in Vietnam. As per custom, the Mongols had metted out savage reprisal on cities; we know from elsewhere that when frustrated, as when denied a chance to meet the foe directly in battle, it only resulted in increased devastation on those they fell across. Crops and rice patties were destroyed by the tred of armies and horses, and we cannot imagine what starvation and horrors greeted the population caught in the middle of this conflict. Many thousands fled into the wilderness to escape the Yuan armies, and few could have been prepared for the experience. Their suffering from disease, lack of water and resources goes unmentioned in the sources. The capital of Thăng Long had been looted and occupied for the second time in thirty years. In Champa the evidence is less clear, but it seems Sogetu burned his way through many of the most prominent city's along the coast in his march north. In the</span> <em><span style="font-weight: 400;">Complete Book of the Historical Records of Đại Việt</span></em><span style="font-weight: 400;">, in the entry for the year 1286 Prince Hưng Đạo provides this assessment to the King:</span></p> <p> </p> <p><em><span style="font-weight: 400;">"Our kingdom has been at peace for a long time. The people do not know about military matters. Previously when the Yuan came and raided, there were those who surrendered or fled. By relying on the potent awe of the imperial ancestors, Your Highness's divine [perspicacity] and martial [awe] wiped clean the dust of the nomadic barbarians. If they come again, our troops are trained at fighting, while their army fears a distant campaign. They are also dejected by the defeats of Heng and Guan. They do not have the heart to fight. As I see it, they are sure to be defeated."</span></em></p> <p> </p> <p><span style="font-weight: 400;">Hưng Đạo, as fitting his character, comes across optimistic and eager to fight. Yet, he recognized that many had quickly defected or routed before the Mongols. The Vietnamese needed to prepare to meet the Mongols again ahead on, rather than simply rely on the 'awe' of the King.</span></p> <p> </p> <p><span style="font-weight: 400;">   </span> <span style="font-weight: 400;">In October 1287, the third invasion began. The army  into three major forces: Toghon took the main army overland, 6,000 traveled west of the main army to act as a diversionary force and 18,000 were taken by Omar and Fan Yi aboard war ships sailing along the coast to find and neutralize the Việt navy. The large transport fleet followed some days behind Omar's armada, anticipating that Omar would have cleared the way of enemy ships for them. In December the main army crossed the border in two columns and defeated several Đại Việt forces, marching to Vạn Ki</span><span style="font-weight: 400;">ế</span><span style="font-weight: 400;">p on the Bạch Đằng River to await the arrival of Omar's fleet, who arrived after fighting off a Vietnamese navy. Despite early success, neither force had brought much for food supplies, expecting to be supplied by the transport fleet.</span></p> <p> </p> <p><span style="font-weight: 400;">   </span> <span style="font-weight: 400;">Toghon waited for the supply fleet until the end of January 1288, but unbeknownst to him much of the supply fleet was blown off course by a storm, and the rest were attacked by the Việt  navy. The commander Trần Khánh Dư held his fleet in secret up a river near the coast at Vân Đồn, and allowed the Yuan warships under Omar to pass by. Once Omar and the warships were beyond reach, Trần Khánh Dư  fell upon the unguarded, slower moving Yuan supply ships. By seizing and scattering these, he ensured the breakdown of the massive Yuan army. With food supplies running low, Toghon marched onto Thăng Long, hoping to resupply there. The city fell without opposition in February 1288, but to their horror they found there wasn't a grain of rice left within: the defenders had once again stripped it in their flight. The increasingly desperate Yuan forces went to great effort to gather food until learning of the disaster which befell the supply fleets at Vân Đồn. Toghon ordered the army back to stockades they had constructed at Vạn Ki</span><span style="font-weight: 400;">ế</span><span style="font-weight: 400;">p, and by the end of March, once his men were on the verge of starvation, he ordered a general retreat back to China. It was now the Việt forces sprung their trap. The Yuan army's route north was harried by continual ambushes and the destruction of roads and bridges to hamper their movements. Arrows flew out from the trees to strike men down. Tropical diseases the Mongols were unused to spread among them, humidity warped their bows and the trees howled with the sounds of alien creatures ensuring sleepless nights. Toghon, great-grandson of Chinggis Khan, showed his pedigree by hiding in a copper tube on the march, then abandoning the troops to board a warship and sail back to the Yuan realm.</span></p> <p> </p> <p><span style="font-weight: 400;">   </span> <span style="font-weight: 400;">On April 9th, 1288, Omar's fleet was sailing past the mouth of the Bạch Đằng river when a group of Vietnamese ships, commanded by Prince Hưng Đạo, sailed out to meet him at high tide. Eager for some sort of victory, Omar took a portion of the fleet and attacked. The Vietnamese routed before the Yuan warships, fleeing back up the river whence they had come. When the Yuan fleet pursued up the river, the trap was sprung: while the smaller and lighter Vietnamese craft had cruised by in safety, wooden stakes placed along the river bottom impaled the larger Yuan vessels, holding them in place as the tide receded. With the Yuan ships immobilized, the Vietnamese turned about and attacked: helpless, many Yuan soldiers jumped into the river, drowning or picked off by the arrows of Đại Việt, and Omar was captured. The other fleet commander, Fan Yi, attempted to rescue Omar, but his vessels were surrounded and boarded, Fan Yi himself killed in the fighting. Some 400 ships were captured, capping off a campaign which saw most of its land forces destroyed in the wilderness.</span></p> <p> </p> <p><span style="font-weight: 400;">   </span> <span style="font-weight: 400;">1288 proved to be a total fiasco for the Yuan. Only a few years after the destruction of the great armada off the shores of Kyushu, another fleet and army were destroyed with little to show for it. Toghon was sent into political exile after both disastrous campaigns, his son another disgrace to add to Kublai's troubles of the 1280s. Unlike earlier, thoroughly planned and prepared campaigns, the Mongol leadership was unable to gather the information they needed to properly orchestrate their attacks. The destruction of the cities did not sway or put adequate fear into the Vietnamese monarchs, the sufferings of the population could not move them and unable to capture the enemy leadership, the Mongol were denied many of the strategic tools they had commonly employed to disable the enemy defense. In the dense and rugged jungles and mountains, the Mongols' greatest tactical advantage, the mobility and range of their horse archers, was neutralized, while the heat, humidity and diseases wrought havoc upon troops and horses unused to such a climate. While victorious in the primary field engagements, the Yuan were unable to transform these battles into strategic successes. And crucially, the Mongols struggled to supply themselves. Small foraging parties could be picked off by the locals, supply lines could more be secured and larger armies were dependent on those supply fleets. When the supply fleets of the third invasion were destroyed by Trần Khánh Dư  at Vân Đồn, the massive army commanded by Toghon became a huge, unreadable, liability. All of these were compounded by the fact the Yuan leadership totally underestimated Vietnamese resilience and the Yuan commander, Toghon, was an inept and inexperienced general: in contrast, the military leaders of  Đại Việt were able to maximize their strengths and strike at the Yuan when they were their most vulnerable. </span></p> <p> </p> <p><span style="font-weight: 400;">While Bạch Đằng was a masterfully executed victory by Prince Hưng Đạo, Đại Việt and Champa had suffered terribly over both campaigns, and both kingdoms, to avoid another invasion began sending tribute and recognized Kublai's authority. Still, their resilience and refusal of either monarch to come before him left Kublai wanting another invasion, the Trần pretender Trần Ích Tầc again readied to be put onto the Trần throne, but as with much else, such thoughts were abandoned on Kublai's death in 1294. After Kublai's death, relations were eased between Yuan, Đại Việt and Champa. The kingdoms in Vietnam paid their tribute, and they were spared another Mongol assault. Relations between Đại Việt and Champa improved, and a marriage alliance was organized. The former Cham Prince Harijit, now King Simhavarman III, married the daughter of the Trần King, only to die suddenly in 1307. The death of the Cham king brought a new round of tension between the two states, eventually turning into a continuous conflict between them that ultimately culminated in the Viet seizure of Vijaya in 1471.</span></p> <p> </p> <p><span style="font-weight: 400;">Today, Bạch Đằng is a highly celebrated episode in Vietnam's history, the tactics and strategy of Hưng Đạo studied by the Vietnamese during the Vietnam war. The introduction of the idea of the nation-state to Vietnam has seen Hưng Đạo turned into a symbol of the nation, a single person embodying the ideals of resistance to powerful, foreign foes. </span></p> <p><br /> <span style="font-weight: 400;">But for Kublai, the disasters in Vietnam were only the start to a rough decade, which we will explore over our next episodes, so be sure to subscribe to the Kings and Generals podcast to follow. To help us keep bringing you great content, please consider supporting us on Patreon at</span> <a href="http://www.patreon.com/kingsandgenerals"><span style="font-weight: 400;">www.patreon.com/kingsandgenerals</span></a><span style="font-weight: 400;">. This script was written and researched by Jack Wilson, with the kind assistance of Phú Võ for accessing Vietnamese and Chinese materials. I'm your host David, and we'll catch you on the next one.</span></p>