Relentless Strategies to Pursue Toghan
During this period, Đại Việt’s army launched continuous assaults, inflicting heavy losses on Toghan’s forces as they attempted to retreat through Lạng Sơn. Toghan’s troops were withdrawing along two separate routes. One formation, led by Siktur, took the western path. Upon reaching Hãm Sa Pass, they faced significant casualties in their encounters with Đại Việt troops and were forced to regroup with Toghan’s main force. After passing through Nội Bàng, Toghan’s troops fell into Đại Việt’s ambushes, where they were attacked from multiple directions in an effort to disrupt the Yuan’s formation. In response, Toghan ordered Vạn hộ Đáp Lạt Xích and Lưu Thế Anh to manage the ambushes while the rest of the army retreated. Despite this, Đại Việt continued their pursuit. Consequently, Toghan commanded Vạn hộ Trương Quân to lead three thousand soldiers to fend off the Đại Việt pursuit. Eventually, Siktur’s troops managed to rejoin Toghan’s forces, but they still faced numerous ambushes along the way.
While Đại Việt military leaders and soldiers were zealously engaging their enemies, they suddenly received orders from the King to halt their pursuit. The intention was to allow Toghan to escape for easier diplomatic negotiations. Đại Việt leaders preferred a peaceful resolution with the Yuan rather than continuing their defensive war. However, some military commanders, notably Prince Trần Quốc Hiện, disobeyed the order, driven by their resentment over the atrocities the Yuan had committed against their homeland. Prince Trần Quốc Hiện utilized spies that had infiltrated the Đại Việt army, turning them to work in favor of Đại Việt instead of the Yuan. These spies provided misleading information to the Yuan military leaders, leading them to believe that Đại Việt had a massive force of 300,000 soldiers at Nữ Nhi Pass and Khâu Cấp Mountain. In reality, most of Đại Việt’s troops were concentrated along the coast to dismantle the Yuan navy, leaving only about 30,000 to 40,000 soldiers stationed near the border.
Caught in this trap, Toghan was compelled to redirect his army via the Lộc Châu route to avoid clashes with Đại Việt’s larger forces. However, the narrow paths forced them to spread out, making them vulnerable to Prince Trần Quốc Hiện’s ambushes. Đại Việt rained arrows down from the high mountains onto the Yuan troops, resulting in numerous casualties. The commander of the vanguard, Abaci, was killed by poisoned arrows. Ultimately, Toghan made his way back to Yuan territory, but upon learning of the Mongol defeat, Kublai Khan furiously exiled Toghan to Yangzhou for life. The Mongols and the Vietnamese agreed to exchange their war prisoners. Although Emperor Nhân Tông was willing to pay tribute to the Yuan, diplomatic relations soured again over the issue of attendance at the Yuan court, leading to continued hostilities.
Upon the court’s return to the capital, most of the palaces lay in ruins. The Retired King had to address the nation’s issues from the Guard’s Hall. The government decided to reduce or exempt taxes for civilians based on the extent of the damage they suffered.
Despite their total defeat, the Yuan remained arrogant in demanding the return of war prisoners. They had attacked Đại Việt twice in four years and faced bitter failures each time. The bad news from the Đại Việt battlefield infuriated Kublai Khan, leading him to banish his own son to Yangzhou. Toghan was barred from returning to Beijing and could never see his father again.
Meanwhile, the Đại Việt government sought to maintain peace and dispatched envoys to the Yuan, accompanying Tích Lệ Cơ, a Yuan Prince, back to their homeland. However, they refrained from bringing any tribute this time, claiming that the recent war and hot weather made it difficult to gather tribute materials and escorts in a timely manner. Kublai Khan responded by placing the envoys under house arrest. In the winter of 1288, another group of Đại Việt envoys visited the Yuan, bringing along some war prisoners as a gesture. Nevertheless, the Yuan continued to demand the release of all war prisoners, including notorious figures like Omar and Batu, who had caused extensive destruction in Đại Việt. They also sent envoys to Đại Việt, insisting that the King visit the Yuan court as a subordinate, warning that Kublai Khan would send an army to conquer Đại Việt if he did not comply.
Despite these demands, Đại Việt refused to acquiesce. The King cited health reasons for not attending the Yuan court. Regarding Omar, the Đại Việt rulers assigned Hoàng Tá Thốn to escort him back to Yuan via sea. However, during the night, when their vessel reached a deep-water area, the sailors sabotaged the ship, causing it to sink. Đại Việt’s government pretended it was an accident and held a ceremonial funeral for Omar in front of the Yuan ambassador. In truth, they could not allow Omar to return alive, as his troops had been responsible for significant destruction and killings in Đại Việt. Allowing him to go back safely would incite outrage among the civilians, especially since he had ordered the desecration of the tombs of the past Trần kings. Kublai Khan and the Yuan court suspected foul play, but they could not find evidence to counter Đại Việt’s claims.
The Yuan’s resentment lingered, and plans for a fourth invasion were set in motion. After all their failures, the Yuan were eager for revenge. They dispatched officials to incite the Southern Yuan tribes in preparation for war, planning to attack from the northwest of Đại Việt to leverage their infantry and cavalry while avoiding direct confrontations with Đại Việt’s navy. However, this would not be easy. By 1288, the Yuan faced instability within their ranks. The rulers’ relentless pursuit of expansion had plunged their people into dire conditions, leading to widespread uprisings. Furthermore, many within the Mongol Empire believed that the Yuan’s power had diminished following their military defeats, prompting them to challenge Kublai Khan’s authority.
Despite this, Kublai Khan remained intent on making Đại Việt a fully subordinate state. He sent an ambassador to Đại Việt, demanding that the King attend the Yuan court as a subordinate. However, this time, it was more difficult for the Yuan envoys to meet the Đại Việt King; they could only gain an audience if he permitted it. Otherwise, they were limited to sending letters. The Yuan’s threats yielded no results.
At one point, Trương Lập Đạo praised Kublai Khan’s humanity and benevolence. Annoyed by this, Đinh Củng Viên, a Đại Việt official, retorted, “If the Mandate of Heaven is so benevolent, wouldn’t it be better if he refrained from provoking wars?” As a result, Trương Lập Đạo returned to Yuan empty-handed.
In 1292, Nguyễn Đại Phạp arrived in Yuan as an ambassador. Upon meeting the Yuan officials at Ngạc Châu, he greeted everyone except Trần Ích Tắc, the treacherous Prince of Đại Việt. Ích Tắc mocked him, asking, “Are you the copier guy at Prince Chiêu Đạo’s place?” Đại Phạp shot back, “Times have changed. I once was the copier guy at Prince Chiêu Đạo’s place, but now I am an ambassador. Just like Bình Chương, who used to be a Prince but now serves the enemy!” From that point on, Trần Ích Tắc avoided Đại Việt envoys.
In 1293, Yuan envoys led by Lương Tằng and Trần Phu returned to Đại Việt. Unable to persuade the King to attend the Yuan court, they demanded that the Crown Prince go instead. Đại Việt rejected this demand but organized a military parade to intimidate the envoys.
Kublai Khan’s desire for expansion to the south persisted, and he still aimed to conquer Đại Việt. In 1293, a minority leader, Hoàng Thắng Hứa, along with his community in both Đại Việt and Yuan, led an uprising against Khan’s regime at Ung Châu. They attacked and retreated into Đại Việt. This happened repeatedly, causing local officials to hesitate to enter Đại Việt territory. The Yuan demanded that Đại Việt capture Hoàng Thắng Hứa and surrender him, but the Đại Việt government ignored this demand, recognizing his contributions to their defensive efforts.
With this context, the Yuan prepared to launch another attack on Đại Việt. However, Kublai Khan passed away before the campaign could commence. The new Yuan ruler, not wanting to initiate another war with Đại Việt, refrained from demanding that the Đại Việt King attend the Yuan court, unlike his predecessor.
See also: Tran dynasty: the dynasty that defeated the Mongols 3 times
