Battle of Bạch Đằng (1288)

In 1287 the Yuan commander Toghan, a son of Kublai Khan, invaded Vietnam for the third time. Under his command were a land force led by himself, and a massive fleet consisted 70,000 regular troops, 21,000 tribal auxiliaries from Yunnan and Hainan, a 1,000-man vanguard under the general Abachi, and 500 ships under the Muslim general Omar (Vietnamese: Ô Mã Nhi) and Chinese Fan Yi (according to some sources, the total Mongol force was composed of 300,000–500,000 men). They also transported 170,000 piculs of grains on Zheng Wenhu's supply fleet, followed the Omar's fleet.[1] After the defeat of the first two invasions, Kublai sent veterans such as Arigh Khaiya, Nasir al-Din and his grandson Esen-Temür.[4] In January 1288, the Vietnamese navy attacked and destroyed the Wenhu's supply fleet, while other Yuan supply fleets were drifted or blown off by strong northeast monsoon's wind.[2] With no sign of Wenhu's supply fleet, still Toghon ordered the Mongol land force one again to occupy Đại Việt's capital Thăng Long and consolidated their occupation of the Red River delta, driving the Vietnamese army and the Royal Family to the coast.[5] However, due lacking of food supplies, in 5 March Toghon and Omar's army from Thăng Long, retreated back their fortified main base in Vạn Kiếp (northeast of Hanoi). As food supplies running low and their positions were untenable, in 30 March, Toghon decided to return to China.[6] Toghon boarded a safety large warship for himself and the Yuan land force could not withdraw in the same way they came. Trần Hưng Đạo, aware of the Yuan retreat, prepared to attack. The Vietnamese had destroyed bridges, roads and creating traps along the retreating Yuan route. They pursued Toghon's forces to Lạng Sơn, where Toghon was forced to abandoned his ship, avoided highway and was escorted back to China by his few remaining troops through the forests.[7] Most of Toghon's land force were killed or captured.[7] Meanwhile, the Yuan fleet commanded by Omar were retreating through the Bạch Đằng river.[6]

Vietnamese boats in Danang, 1828, pictured by John Crawfurd

The Bạch Đằng River ran through Yen Hung district (in Quảng Ninh province) and Thuy Nguyen (in Hai Phong) before reaching the sea. This was where the earlier well-known battle of Ngô Quyền against the Southern Han had taken place in 938.[8] Beginning from March, Trần Hưng Đạo began preparing the battlefield. He used the same tactic that Ngô Quyền had against the Chinese in 938. He studied the tidal lore, and ordered beds of stakes to be planted under the water and arranged ambushes in a unified plan of campaign.

Trần Hưng Đạo ordered his soldiers to nail the iron-headed poles under the waters of the Chanh, Kênh and Rút rivers. All three rivers are the northern distributaries of the Bach Dang River. Ghềnh Cốc is a reef located across the Bach Dang to the bottom of Chanh river and to the top of Kênh river. Ghềnh Cốc was used as a place for the ambush, in collaboration with the underwater iron-headed poles. They were to block the enemy ships when the tide withdrew. Đại Việt's small flotilla secretly stationed themselves behind Ghềnh Cốc, Ðồng Cốc, Phong Cốc and on the Khoái, Thái, Gia Ðước, and Ðiền Công rivers. The army deployed in Hung Yen, along the left bank of the river Bach Dang and Tràng Kênh, at the right bank of Bach Dang River and Mount Ðá Vôi.

In early morning of 9 April, the naval fleet led by Omar, and escorted by infantry, fled home along the Bạch Đằng river.[7] They entered Hưng Đạo's trap when it was high tide. A small fleet of Vietnamese junks sailed opposed and attacked the Yuan fleet, then retreated. Then the tide receded while Yuan fleet pursuing and battling Vietnamese junks, revealed wooden stakes planted into river. With the Yuan fleet stuck in the trap, the Vietnamese junks with bombs (震天雷) returned and destroyed the immobilized Yuan warships. Thousands of Mongol troops jumped into the river and were killed or drowned.[7] Fan Yi, seeing Omar's fleet being destroyed, his commanding fleet was surrounded by Vietnamese small junks. Tried to espace, Fan Yi jumped into the river, but was fished by the Vietnamese. The battle lasted from sunrise to sundown (5am-7am to 5pm-7pm) as in end of the day, the Vietnamese captured 400 Yuan warships.[7]

The supply fleet of the Yuan dynasty was totally destroyed, and Omar was captured by the Vietnamese.[7]

17th-century model of a Vietnamese mông đồng fighting boat, a type which probably had constituted much of the Vietnamese naval fleet 400 years earlier

Upon receiving news of the Mongol defeat, Kublai angrily banished Toghan to Yangzhou for life. The Mongols and the Vietnamese agreed to exchange their war prisoners. While the king Trần Nhân Tông was willing to pay tribute to the Yuan, relations again foundered on the question of attendance at the Yuan court and hostile relations continued.[7] In 1289, King Nhân Tông agreed to sent back his prisoner Omar, but Prince Hưng Đạo who opposed this gesture, contrived have the ship transporting Omar sink at sea.[9]

The Vietnamese monarch Trần Nhân Tông eventually decided to accept the supremacy of the Yuan dynasty in order to avoid further conflicts. Because he refused to come in person, Kublai detained his envoy, Đào Từ Kí, in 1293. Kublai's successor Temür Khan (r.1294-1307), finally released all detained envoys, settling instead for a nominate tributary relationship, which continued until the end of the Yuan dynasty.

• Battle of Bạch Đằng
• First Battle of Bạch Đằng
• Trần dynasty

• Karnow, Stanley (1983), Vietnam: A History, New York: Penguin Books, ISBN 0-14-007324-8
• Elleman, Bruce A. (2012), China as a Sea Power, 1127-1368: A Preliminary Survey of the Maritime Expansion and Naval Exploits of the Chinese People During the Southern Song and Yuan Periods, U.S. Naval War College: NUS Press, ISBN 9789971695057

• https://web.archive.org/web/20090304011202/http://vietnamnews.vnagency.com.vn/showarticle.php?num=04SUN220106