Battle of Bạch Đằng (938)

In 931 AD, Dương Đình Nghệ defeated the Southern Han army – one of the Ten Kingdoms near Tĩnh Hải Quân (Army of the Peaceful Sea, the name used for Vietnam's army at that time) and achieved the independent status of the Vietnamese at Tĩnh Hải quân; he named himself Jiedushi and was recognized by the Later Tang court.[4]

In 937 AD, Đình Nghệ was killed by Kiều Công Tiễn, revoking the title of Jiedushi. Đình Nghệ's son in law and also his general, Ngô Quyền mobilized his army to exact revenge on Công Tiễn.[4]

Fearing Ngô Quyền, Công Tiễn requested help from the Southern Han. Thenceforth, the emperor of the Southern Han, Liu Yan, took his chance and prepared to invade Tĩnh Hải (the Peaceful Sea) again.[4]

Liu Yan claimed that if Dương Đình Nghệ was dead, then Tỉnh Hãi Quân would be deprived of good generals. He ordered his ninth son, Liu Hongcao (Vietnamese: Lưu Hoằng Tháo) to become "Bình Hải tướng quân" (Sea-Pacifying Military General) and "Giao Chỉ vương" (King of Giao Chỉ), he commanded the naval forces of the Southern Han into Giao Chỉ.[4]

In 937, Liu Yan (Chinese: 劉龑; Vietnamese: Lưu Nham), the Southern Han ruler took the chance to intervene in Vietnam after the death of the Annam Lord Protector Dương Đình Nghệ. Liu Yan had been previously defeated by Dương Đình Nghệ in 931. Liu Yan placed his son, Liu Hongcao (Chinese: 劉弘操; Vietnamese: Lưu Hoằng Tháo), in command of the expedition, naming him "Peaceful Sea Military Governor" and "King of Giao." He assembled an army and took charge of the reserve force. He ordered Liu Hongcao to embark the army and sail to Giao.

By the time Liu Hongcao and the Southern Han expedition arrived in Vietnamese waters, Liu Hongcao's plan was to ascend the Bạch Đằng River and to place his army in the heart of Giacannoto Chau before disembarking. The Bạch Đằng was the major riverine route into the Red River plain from the north.

Ngô Quyền anticipated this plan and brought his army to the mouth of the river. He had his men plant a barrier of large poles in the bed of the river. The tops of the poles reached just below the water level at high tide and were sharpened and tipped with iron. When Liu Hongcao appeared off the mouth of the river, Quyen sent out small, shallow-draft boats at high tide to provoke a fight and then retreat upriver, drawing the Chinese fleet in pursuit. As the tide fell, the heavy Chinese warships were caught on the poles and lay trapped in the middle of the river, whereupon they were attacked by Ngô Quyền's forces.

More than half the Chinese drowned, including Liu Hongcao.[5] When news of the battle reached Sea Gate, Liu Yan wept openly. He collected what remained of his army and returned to Canton. This victory ended China's long occupation of Vietnam and began a period of Vietnam's independence until the conquest by the Ming China. Ngô Quyền's tactic would later be reused by Trần Hưng Đạo in a battle at Bạch Đằng River against the Mongols in 1288.

The military tactics employed by Ngô Quyền were original, as Lê Văn Hưu described: "Great tactic, good combat" (Original:"善謀而善戰者也/thiện mưu nhi thiện chiến giả dã" Modern Vietnamese: "Mưu giỏi mà đánh cũng giỏi") in the Complete Annals of Đại Việt.[6][7] However, according to military historians, applying a pole-and-tide stratagem to inflict damage upon an enemy navy required the successful combination of two factors:

• Lure the enemy past the poles when at high tide as the poles are hidden.
• Know the tide and calculate the time when the tide ebbs, and ensure the enemy ships are above the poles at this moment.

These two circumstances were integrally linked, for if the enemy came in at low tide, they would have seen the poles. If low tide did not set in at time, Liu's boats would have easily sailed over the poles. Therefore, for this tactic to take effect, beside preparing the poles secretly and quickly, luring the enemy onto the right route at the right time was the most decisive factor.

Ngô Quyền knew of Hongcao arrival, and told his generals:[4]

Hoằng Tháo (Hongcao) is such a foolish child, leading his army from a far land. His soldiers were still tired, and eventually they became completely perplexed when they heard that Công Tiễn was killed and there was no information about the situation happening right here. Our army is strong, the enemy is weak; we can surely win victory in this war. However! They have an advantage with their mighty war ships, and if we don't plan our defence first, we don't know who will control the battle. If we order our men to place iron-headed poles under the water of the sea gate, their ships will follow the tide of sea and be caught upon the poles, and then we can easily dominate them without letting any ships of theirs escape.

— Ngô Quyền

Ngô Quyền ordered his soldiers to place the iron-headed poles in the waters of the Bạch Đằng river. At high tide, the poles would be covered with water, and thus, remain unseen by the Chinese. Ngô Quyền intended to lure the enemy into this area when the tide was up. When the tide was down, the enemy's boats would be stranded, and be easy targets for attack.[4]

Model of Battle in Bach Dang River in 938 AD

On a late winter day in 938 AD, on Bạch Đằng River, the entire Han's naval fleet led by Hongcao entered Tĩnh Hải.[4]

The Southern Han's soldiers, seeing the small ships of Ngô Quyền, aggressively marched in, thinking that they could easily defeat the small force of Ngô Quyền. Ngô Quyền ordered his army to retreat upstream. He waited until the tide lowered and ordered his army to fight back. The ships of the Southern Han were stuck and penetrated by the poles. At that time, Ngô Quyền used all of his forces to attack. The Southern Han's Army lost the battle and retreated, Liu Hongcao and more than half of the force was killed by the Vietnamese.[4]

The Emperor of the Southern Han was leading his army at the border, so he could not respond to the situation. Hearing the news that Hongcao was dead, Liu Yang was horrified, and ordered his remaining forces to retreat.[8] After that, the Southern Han abandoned the invasion of Tĩnh Hải quân.[8]

By the year 939, Ngô Quyền became King, took the title Ngô Vương (Ngô King) and founded Vietnam's Ngô Dynasty with his capital at Cổ Loa (Today's Đông Anh, Hà Nội).[7]

General Trần Hưng Đạo reused this tactic in the Battle of Bạch Đằng (1288). He fully understood the requisites behind this tactic and applied them successfully by pushing a Mongol army out of the Bạch Đằng River.[9]

In 938 AD, after calling a large number of soldiers to his side, Ngô Quyền led his army from Ái Châu to the North to attack Kiều Công Tiễn. Công Tiễn was surrounded by Ngô Quyền's army and failed to break out. He waited for the reinforcements of Southern Han.[4]

Liu Hongcao led over twenty thousand troops into Giao Chỉ to reinforce Công Tiễn's army.[4] Liu Yan sought advice from Chongwen's courtier (known by the Vietnamese as Tiêu Ích). Ích said:

Nowadays, rain has fallen for weeks, and the sea's route is dangerous and long. Ngô Quyền was also a talented tactician; we cannot despise him. Our army must be so-cautioned, we should use as many scouts as possible while moving forward (cautiously) to the South.

— Chongwen's courtier Tiêu Ích

However, the Han Emperor wanted to move fast and quickly reconquer Tĩnh Hải, so he ignored the warning from Tiêu Ích. He ordered Hongcao to lead his army to the river of Bạch Đằng immediately. Emperor Liu Yan, a general himself, stayed at Haimen as an alternative reinforcement.

While Liu Yan was mobilizing his army, Ngô Quyền marched to Đại La to attack Kiều Công Tiễn. Công Tiễn was completely enveloped by Ngô Quyền's forces and was killed before the Southern Han's reinforcements had a chance to march into Vietnam.[4]

In 939, the newly Ngô Dynasty was recognized by the Later Jin court as an independent country.

Tiền Ngô Vương could take the newly raised soldiers of Viet to defeat thousand troops of Lưu Hoằng Tháo, created the country and claimed himself King, made the Northerns feared as they didn't want to come again. We could say this is a wrath to ease the people, great tactics, good combat too. Although he just claimed himself a king, not fully heir to it, changed his title, but the formal of our Đại Việt, His Ancestor reconnected it.

— Ngô Sĩ Liên[7]

By the first century CE the population of the Han empire exceeded 57 million, while in Vietnam lived just over 1 million people. After the conquest of Chinese-founded state of Nanyue, the Han rulers undertook the process of direct and indirect assimilation of the people into the Han Empire. The assimilation policies is a common feature of Chinese dynastic expansion and was implemented in various forms from the Han Dynasty to the Tang.[10]

Ngô Quyền – the commander at the Battle of Bạch Đằng in 938 is known among modern Vietnamese people as The King who rebuilt Vietnam Đại Việt sử ký toàn thư.[8] The people and nation of Vietnam consider this victory to be of fundamental significance for their national identity. The author Phan Bội Châu remarked of Ngô Quyền: "He truly deserves the title "Middle-Ancestor" of the Vietnamese people."

The victory of Bạch Đằng marked the beginning of a new age for the Vietnamese people, who undertook large-scale rebuilding and restoration efforts. Known as Đại Việt (Great Viet) this era is a golden age of powerful dynasties, like the Lý Dynasty, the Trần Dynasty and the Lê Dynasty, who resided ruled at the Imperial Citadel of Thăng Long.[10]

Historian Ngô Thì Sĩ described:

The Victory on Bạch Đằng River is the basis to rebuild the nation. The victories under the Đinh, Lê, Lý, Trần's Dynasty after then also followed the prestige this victory left. The Battle of Bạch Đằng has great fame, resounding through thousands of Autumns, not only glorious in its own time.

— Việt sử tiêu án[10] - Ngô Thì Sĩ

• Battle of Bạch Đằng (981)
• Battle of Bạch Đằng (1288)
• Đại Việt sử ký toàn thư

• Xa Bach Dang Dong Hung Thai Binh Viet Nam