The people living in what is today Vietnam
have long been famous for their resistance against great empires, and their spirited
defence against Mongol invasions is indeed no exception. In this part of our series
on how to defend against the Mongols, we see how the two kingdoms in what is
today Vietnam: Đại Việt in the north and Champa in the south, went about defending
their independence against the incursions of Khubilai Khaan’s Mongol-ruled Yuan
Dynasty in the late-thirteenth century. This video was sponsored by MagellanTV. To
learn more about our favorite documentary platform and the Vietnam War and
get their offer for our viewers, watch the message at the end of the video. The Kingdom of Đại Việt, or Annam as it was known
to the Chinese, had dominated the northern part of Vietnam since the start of the eleventh century,
centered around the Hong River with their capital at Thăng Long, modern day Hanoi. Predominantly
Buddhist and wealthy through a rich agricultural base, in the 1220s, the ruling Lý Dynasty of
Đại Việt was succeeded by the Kings of the Trần family. The new Trần Dynasty reformed the
kingdom, centralizing power and expanding their agricultural base, strengthening the kingdom.
Chinese was the official language of the court, and Trần made good relations with its
neighbours: the Song Dynasty to the northeast, to which Đại Việt paid tribute and nominal
allegiance in exchange for 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.
The Chams are a part of the far-flung Austronesian people, inhabiting central and southern Vietnam
for millennia. For most of their history, they were a collection of small, competing Hindu and
Muslim kingdoms. However, in the twelfth century, they entered a new period of unity in the face
of an invasion by the Khmer Empire of Cambodia, the builders of Angkor Wat. United under
a ‘king of kings,’ the Chams repulsed both the Khmer and Đại Việt when they invaded Cham
lands. Though not as centralized as Đại Việt, from the mid-twelfth century onwards, the King of
Kings based out of the city of Vijaya wielded more influence over the other Cham kings and princes—
this was the nature of the kingdom of Champa. This was the political situation in Vietnam when Mongol
armies arrived in the mid-thirteenth century. Đại Việt was the first to encounter Mongol
armies. In 1253, on his brother's orders, the Grand Khan Möngke, prince Khubilai, marched
into Yunnan and conquered the Dali Kingdom. Though Khubilai returned north, his general Uriyangqadai
stayed in the region and continued to subdue the local peoples. Uriyangqadai, the son of the famous
Sübe’edei, led a series of wide-ranging campaigns across Yunnan, the edges of Tibet, to the small
kingdoms on the southwestern edge of the Song Dynasty. In this process, Uriyangqadai came to the
northern border of Đại Việt. The Mongols expected the submission of Đại Việt, but given that the
entire aim of the campaign was to open a new front in the Song War, Đại Việt was not a primary
target. The immediate strategic concern was to prevent the Trần kings from offering any support
to the Song Dynasty. Möngke Khan was planning a massive, three-pronged assault upon the Song for
1258 and needed Uriyangqadai’s forces to meet their schedule . With Đại Việt’s considerable
trade and tribute contacts with the Song, the Mongols wanted to know if the kingdom would not
harass Uriyangqadai’s army. He sent envoys to the Trần court at Thăng Long asking for free passage
for the army but received no response. Cautiously, in the winter of 1257, Uriyangqadai and his son,
Aju, entered Đại Việt with 10-30,000 men, Mongols supported by locally raised troops from Yunnan.
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 attacked the Việt, and a frustrated Uriyangqadai then advanced to
support him. Despite the insubordination and the Việt war elephants, the Mongols had the better
of the battle, with Mongol archers focusing on the elephants’ eyes. However, a defiant rearguard
allowed the Trần leadership to escape the battle via ship, and the always-strict Uriyangqadai
ordered the execution of that vanguard commander. The Trần forces' effort to stop the Mongols
from crossing the Phù Lỗ river was foiled when the Mongols found a ford to cross and then rout
the Trần army. Uriyangqadai then marched onto the capital city, Thăng Long, only to find
it abandoned. The Trần King, the government and most of its population had evacuated the
city, taking most of the foodstuffs with them. Vietnamese and Chinese sources differ on
precisely what followed. Uriyangqadai, at least, withdrew and was harassed by local forces as they
went. The Trần King then offered tribute to keep the Mongols at bay. While ambushes, heat, humidity
and tropical disease can be blamed, Uriyangqadai simply did not have time to stay in Đại Việt
any longer due to Möngke Khan’s timetable. After the withdrawal, Uriyangqadai was crossed
into the Song Dynasty’s southwestern border in a failed effort to link up with Möngke Khan.
The Trần Kings anticipated a continuation of their relationship with the Song, giving tribute
every few years to keep the peace and enrich both parties, and Champa followed suit. The Mongols
were willing to accept this for a few years, but Möngke’s brother and successor Khubilai Khan
began demanding the Trần and Cham kings confirm their allegiance in person to him. With the
fall of Song in 1279 to Khubilai’s Yuan Empire, there was no buffer between them. Khubilai grew
impatient as Đại Việt and Champa sheltered many refugee Song officials. By 1280 Khubilai demanded
that if the Trần king could not come in person, he must send a massive golden statue
of himself and increased tribute to the kingdom’s most skilled doctors, artisans,
scholars and most beautiful women. They refused. This was perceived as insubordination, and
once the Chams imprisoned Yuan envoys in 1282, Khubilai had his pretext for war. Striking at
Champa first could place Đại Việt in a vice grip between Yuan China and an occupied Champa. The
politically fragmented Champa must have seemed an easy target, Khubilai’s officials telling him
less than 3,000 men would be needed to overrun the Chams. After the failure of the second invasion
of Japan in 1281, Khubilai was also hungry for victory. Worn out by the intensive 1270s, by the
1280s, Khubilai was no longer a patient man and had outlived his wisest advisers and most veteran
commanders. Having come to expect total victory, Khubilai now demanded it immediately.
In December 1282, Sogetu, the governor of Fujian, departed with 5,000 men from former
Song lands aboard a hundred ships, arriving near the Cham capital of Vijaya in February 1283.
Though the city fell after a short fight, the Cham leadership, King Indravarman V and
Prince Harijit, escaped into the mountains. Sogetu tried to pursue, but in the jungle, his
men were ambushed and driven back, and Sogetu retreated to the coast to dig in and ask for aid.
The Yuan court’s response was slow, still planning for a third invasion of Japan. Only in March
1284, once the third Japanese invasion was finally abandoned, was an army of 20,000 dispatched by
sea to aid Sogetu. Delayed by a brief mutiny, they arrived the next month to link up with
a 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. By August 1284, Khubilai’s eleventh son Toghon
was ordered to march through Đại Việt to assist Sogetu. The Yuan ordered the Trần King
to supply this army, but they refused, expecting a trap. At that time, the
reigning King was Trần Khâm . His father, the previous king Trần Thánh Tông, was still
alive but ‘retired,’ abdicating the throne to act as ‘emperor-emeritus’ for his successor while
avoiding that strict court protocol. According to a later chronicle , the ‘emperor-emeritus’ Trần
Thánh Tông, summoned elders and advisers from across Đại Việt to discuss the best course of
action. Supposedly, they all shouted in unison, “Fight!” And so, the Trầns began to prepare
for the assault, readying officers and men. Of these, one man is the most famous: Trần
Quốc Tuấn, known better by his later title, Prince Hưng Đạo. The nephew of the first
Trần King and son of a traitorous father, Hưng Đạo was a shining beacon of loyalty
and filial piety. Alongside his charisma, his natural talent and skill made him a favourite
for chroniclers to fawn over. One notable blemish marked his character: as a young man, Hưng
Đạo had an affair with an imperial princess engaged to another man. With the oncoming Mongol
threat in 1284, Hưng Đạo marked himself out by his preparations, training men and officers before
taking a leading role in the strategy himself. In January 1285, Khubilai Khaan’s son
Toghon and an Uyghur general, Ariq Khaya, led some eight tumens from Yunnan into Đại Việt.
Accompanying them was 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. Another column
came from the northwest under Nasir ad-Din, who had previously fought in Burma and was a son
of the Central Asian Muslim who governed Yunnan. Việt border troops were quickly overcome, and the
Yuan advanced south while Sogetu headed n orth, a great pincer movement on Đại Việt. Prince
Hưng Đạo tried to delay Sogetu but was repulsed, with Sogetu capturing 400 renegade Song officials
from Hưng Đạo’s army. By the time Sogetu linked up with Toghon, the Yuan had an entire river
fleet under the command of Nasir al-Din’s son, Omar. Omar chased the Trần King to sea while
Toghon and Sogetu captured Thăng Long. Armies sent against them were annihilated, and many
Trần generals defected to the Yuan forces. But this was the final success of this campaign.
Again, Thăng Long had been evacuated to deny the Mongols. Yuan forces and supply lines were
overextended, running low on food while heat and disease took their toll. The Việt troops also
employed psychological warfare on the Yuan. In June, one of the Yuan generals was killed, and
ambushes ravaged his army. A former Song Dynasty officer and his entourage, fighting alongside
Việt troops, donned their old armour to panic some Yuan detachments, many of whom were former
Song subjects. The fallen Vietnamese had tattooed “kill the Tatars!” on their bodies, angering,
frustrating and frightening Yuan forces. Toghon, deeming the position untenable, ordered a
poorly-organized retreat, which left Sogetu and his army behind. Sogetu attempted to fight
his way north, only to be captured and killed, his army surrounded and destroyed.
The Việt campaign was a fiasco, one of Khubilai’s own sons failing to deliver victory.
Khubilai was so furious he refused to allow Toghon in the capital and ordered a third attack. The
Trần pretender Ích Tầc once more joined them, and great effort was taken to prevent a repeat
of logistical issues. A fleet of supply ships was assembled on the southern Chinese coast to
ferry troops and provide the food necessary for an army assembled from across the Yuan realm
, perhaps 100,000 men, in addition to 500 warships and transports. Toghon was given a final
chance to redeem himself before his aging father. It should not be imagined that Việt and
Champa were unscathed. The Mongols had meted out savage reprisal on any city that
fell. Crops and rice fields were destroyed, starvation and horrors greeting the population
caught in the middle. Thousands fled into the wilderness to escape the Yuan armies: their
suffering from disease, and 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
cities along the coast in his march north. The third invasion began in October 1287.
Two armies marched overland, the main led by Toghon. On the sea, Omar and Fan Yi led warships
hunting for the Việt navy. The large transport fleet followed some days behind Omar’s armada.
Toghon’s troops defeated several Đại Việt armies, marching to Vạn Kiếp on the Bạch Đằng River to
await the arrival of Omar’s fleet, who arrived after their own victories. Despite early success,
neither force had enough supplies, relying on the transport fleet. But that fleet was dispersed by
a storm and then destroyed by the Việt navy, which under Trần Khánh Dư had avoided Omar’s warships.
With this maneuver, the Yuan plan was broken. Food supplies ran low, and Toghon again took Thăng
Long in February 1288, only to find it stripped bare again. Once Toghon learned of the loss of
the supply fleets, he withdrew to the stockades they had constructed at Vạn Kiếp, and by the end
of March, with his men on the verge of starvation, he ordered a general retreat. Now, the Việt
forces sprung their trap. The Yuan army’s route was harried by ambushes and the destruction
of roads and bridges to hamper their movements. Tropical diseases spread among malnourished men
and beasts, 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 to sail home.
On April 9th, 1288, Omar’s fleet was sailing past the mouth of the Bạch Đằng river when Việt ships
led by Prince Hưng Đạo sailed out to meet him at high tide. Omar took the bait. Hưng Đạo fled back
up the river, Omar in pursuit. Hưng Đạo smaller and lighter craft cruised by in safety, but 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, Hưng Đạo attacked: helpless, many Yuan soldiers
drowned in the river or fell to the arrows of Đại Việt, and Omar was captured. The other
fleet commander, Fan Yi, attempted to rescue Omar, but his vessels were boarded, Fan Yi himself
killed in the fighting. Some 400 Yuan ships were captured, capping off a campaign which saw most
of its land forces destroyed in the wilderness. 1288 proved a total fiasco. 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 Khubilai’s troubles of the 1280s.
The Mongol failure cannot simply be reduced to the jungle. It was a factor, as the tropical
heat, humidity, and disease wore down troops unused to the environment, but we can identify
more immediate causes. The destruction of the cities was an insufficient threat, and
unable to capture the Việt or Cham Kings, the Mongols were denied their tools to disable
the enemy defense. The Mongols struggled to supply themselves due to ambushes or vulnerable supply
fleets. Most importantly, Yuan leadership totally underestimated Vietnamese resilience, hampered
by the inept and inexperienced Toghon and a demanding, unrealistic Khubilai. In contrast,
the military leaders of Đại Việt, skilled men like Prince Hưng Đạo, learned from their mistakes,
maximized their strengths and struck the Yuan when they were most vulnerable. While often victorious
in the initial field engagements, the Yuan could not turn these into strategic successes.
Still, both Đại Việt and Champa had suffered terribly over both campaigns, and Khubilai
threatened another attack until his death in 1294. After that, relations eased between Yuan, Đại Việt
and Champa. The kingdoms in Vietnam paid tribute to the Yuan Khans for trade access, gave a nominal
submission and were spared another Mongol assault. Vietnam had a long and tragic history of foreign
invasions, but the Vietnamese seemingly always found a way to defend their country. Our friends
at MagellanTV have an excellent 3-episode documentary series called The Vietnam War that
tells the compelling story of the Vietnam War, beginning with the country’s dynastic history.
It details the impact of Christian missionaries and French colonialism, Japan’s invasion during
WWII, the rise of Ho Chi Minh, and how the USA’s fear of Communism started a relentless sequence
of events that caused American troops to go in under President Kennedy in 1961. The conflict
escalated under Lyndon B. Johnson in 1965 when the nation was entwined in a war fought nightly on
TV, engendering a huge antiwar movement. By 1975, Nixon had resigned, and America was forced to
withdraw from Saigon. MagellanTV has hundreds of documentaries tailored for history fans
and beyond. That is only the beginning of Magellan’s collection, and there’s plenty of
stuff from outside the realm of history as well, and more and more being added constantly. For
some high quality history content, use our special link in the description, and MagellanTV
will give you a month of access for free! Our series on how the various peoples defended
against the Mongols will continue in the near future, so make sure you are subscribed
and have pressed the bell button. Please, consider liking, commenting, and sharing; it helps
immensely. Our videos would be impossible without our kind patrons and youtube channel members,
whose ranks you can join via the links in the description to know our schedule, get early
access to our videos, access our discord, and much more. This is the Kings and Generals
channel, and we will catch you on the next one.
