Ly Thuong Kiet Dai killed the precepts in front of Bach Dang gate

The navy was an important part of the entire Song invasion plan. As the previous periods said, the Song navy of this period was a “seasonal” army, hastily built up just to serve the annexation of Dai Viet. The soldiers of the Song navy were mostly coastal people who were recruited and trained for a short time, while the ships were converted merchant ships. In terms of quality, the Song navy was far inferior to Dai Viet both in terms of soldiers and boats. Because Dai Viet is a country with a strong cultural base of rivers and seas, a territory with many rivers and sea borders, it often has to use its navy for conflicts with Champa and defeat in the country.

However, the expectations of the Song court and General Quach Quy in the Song navy were not illusory or unfounded. With the potential of an empire many times larger and more populous than Dai Viet, the Song country tried to use its quantitative advantage to compensate for its weakness in quality. The merchant ships that Tong chose to confiscate for use by the navy were large sea-going ships that could both carry many soldiers and reduce wobble when moving. The Song navy had hundreds of large ships. Each can carry more than a hundred soldiers to hundreds of soldiers.

The number of the army of the Song navy, according to the book The art of fighting and defending the country of the Vietnamese people there were more than 50,000 troops, led by General Duong Tung Tien. Duong Tung Tien was appointed by King Tong as An Nam to run the Chien Do Giam camp, in collaboration with a number of other officials in charge of recruiting troops, requisitioning boats to drawing up a battle plan. The Song navy was completely outnumbered by Dai Viet’s navy in the northeast, commanded by Ly Ke Nguyen. According to the book, Ly Ke Nguyen’s navy was only under 20,000 soldiers Vietnamese famous generals It is estimated that even the entire Dai Viet naval force is less than the number of the Song navy.

According to the original plan that the commander-in-chief of the Tong navy – General Duong Tung Tien outlined, was to use the navy to circumnavigate the sea to enter Champa territory, coordinate with the Champa army to fight back from the south of Dai Viet. form a pincer position. However, in the process of implementation, this plan proved too much for Tong. Because sending tens of thousands of marines to such long distances by sea requires too great logistical preparation, while the preparation time is limited. Such logistical preparation was beyond the potential of any country at that time, including Song. Due to the bankruptcy of the plan to cross the sea into Champa, the Song navy had to switch to a new plan. It was following the northeastern coast of Dai Viet to infiltrate inland along the confluence of the Bach Dang River, coordinated with Quach Quy’s infantry, and transported troops to the big river to capture Thang Long citadel.

The Song navy assembled in Kham Chau, in late autumn 1076 crossed the sea and entered the border of Vinh An province, which General Nham Khoi’s army had occupied before. At Vinh An, Dai Viet troops withdrew to temporarily surrender the battlefield to the enemy. Ly Ke Nguyen quietly let his naval forces set up ambushes in the Dong Kenh River, the arterial route that he expected that the Song navy would have to pass through. Because that is the most reasonable explanation for the Song army to invade Vinh An very early. Dong Kenh was originally a coastal strip of water between the mainland and ports from Vinh An to Bach Dang.

As expected, General Duong Tung Tien and Tong’s navy entered Vinh An without seeing any resistance from Dai Viet’s navy, so he ordered the whole army to line up along the Dong Kenh river to rush towards the river mouth. Bach Dang, right into the ambush field of Dai Viet army waiting. Ly Ke Nguyen gave the order to attack, Dai Viet’s navy used all its strength to fight fiercely on the enemy boat formation. At this time, all the weaknesses of the Song navy were revealed. The large, slow-moving Tong boat was quickly surrounded by real Dai Viet ships and destroyed each one. The soldiers of the Song dynasty did not know how to cope and were bathed in blood by the Dai Viet army. The broken Song army could not be saved, but because the Song navy was very large, the Dai Viet navy could not kill it.

Duong Tung Tien retreated his boat to the mouth of the Dong Kenh River in the north to correct the entrenched forces. The Dai Viet army pursued and fought more than 10 large and small battles with the Song army and always won, tens of thousands of Song sailors left their bodies at the bottom of the water. Duong Tung Tien also had to order the navy to flee to the sea, retreat to the waters of Kham Chau and Liem Chau to set up a water camp. Now not only could not advance the army, on the contrary, the Song navy was also worried that Dai Viet’s navy would overflow into the port of Song. Duong Tung Tien did not dare to return, so he let the boat hover over the sea for several months and sent a letter to the mainland, Tong warned to be on guard:“Recently, I met the enemy’s liaison troops with orders from the enemy’s envoy to the army, Ly Ke Nguyen. After that many times I hit them, but they didn’t mean to give in. So please order strict precautions at the border to avoid surprises.”

Two effective members, Phan Thuc, Hoang Tong Khanh and a small group of boats were sent by Tung Tien to cross the sea to Champa to urge Champa to quickly advance against Dai Viet from the south. But this is also a futile job. Because the straight line was almost impossible to go due to the blockade of Ly Ke Nguyen’s navy, but going around to sea, the sea route was too far away, it was difficult to promptly send information to Champa to coordinate with Song. This was also superfluous, because before the arrival of Champa, he agreed to join the war and in fact, Champa also attacked Dai Viet.

Thus, the Song navy was of no help to the Song infantry except to disperse a part of Dai Viet’s army to the northeastern coastal front. Ly Ke Nguyen and his navy under his command firmly patrolled the northeast coast, completely controlled the front and cut off all communication between the navy and the Song army on land. Failure is a short term to describe the Song army’s waterway front. The sloppy fleet of boats under Duong Tung Tien’s command returned to the Song country at the end of April 1077, when the war was over.