Tây Sơn military tactics and organization

Army

• Infantry
• Cavalry
• Artillery
• Elephantry

Navy

There are 673 warships, 53.250 soldiers under rules of Vũ Văn Dũng admiral.^{[4] [5]}

There are two types of functions:

- Big boats to carry troops, food and other goods.

- Light and flexible boats used to encircle, attack and shock.

There are five types of warfare:

- Type-1 battleship:^[6]

9 battleship, 700 soldiers / each, equipped with 60 cannons, each shot fired about 11 kg. This demonstrates that the firepower and the naval forces on the Tây Sơn warships were extremely strong and numerous. The largest boat in Tây Sơn is known as "Định Quốc" (today calls class warship), the Nguyễn dynasty itself calls it the "Đại hiệu". The Hoàng Lê nhất thống chí booklet describes the boat is "Đại hiệu" as a mobile fort, on "setting up a hut, putting a big gun".

5 battleship, 600 soldiers / each, 50 guns, each shot fired about 11 kg.

- Type-2 battleship:

40 battleship, 200 soldiers / each, 16 cannons, each shot fired in half, weighed 5,4 kg each. This is a type of boat that is both effective in naval warfare, effectively attacking enemy ships by speed and firepower, and transporting many troops, capable of attacking enemy at distant targets.

- Type-3 battleship:

93 battleboats, 150 soldiers / each, equipped with only one cannon, but larger than any other artillery, fired approximately 16,3 kg/shot.

- Type-4 battleship:

300 gunboats, 50 soldiers / each, 1 small cannon.

- Type-5 battleship:

100 sailboats, 70 soldiers / each. And many other types of small boats.

Type-4 battleship and Type-5 battleship: are small, but are rated as very good. Because small to easily handle, if fight on the river it will run by oars, the number of sailors enough to rowing; should be effective in navigating the river, transporting troops to attack the enemy from distant place.

In 1788, Nguyễn Huệ was dissolved with Nguyễn Nhạc in the South Vietnam and was pressured from the North Vietnam when the Qing Dynasty prepared to send troops to attack, the more he urged the naval organization to deal with the increasingly drastic situation. General Bảo was given 16 more boats and more vehicles to recruit troops.

Barizy (French naval officers in the Nguyễn lords ranks) reported on the forces of the Tây Sơn fleet led by Vũ Văn Dũng as follows:

"This force consists of 673 small and large vessels. In these numbers, there were larger ships armed with cannon and crew than the largest Western-style warships the Nguyễn Ánh had."

In a letter from Jeaptiste Chaigneau, in Quy Nhơn, the Tây Sơn navy had 54 battleships, 93 battleboats, 300 gunboats, and 100 sailboats.

In a letter dated April 11, 1801, Barizy sent Letondal to write about the naval battle of Thị Nại in 1801, stating that the Tây Sơn navy had 4.800 transport boats in Thị Nại harbor.^[7]

Commander^[8]

Not rush, hide force, reconnaissance first

When Tây Sơn army advancing to the South Vietnam, in preparation for fighting the Siamese army, Nguyễn Huệ did not enter Gia Định, he camped his force in Mỹ Tho, to conceal the force and conduct it, scouting the situation to design a fight plan against Siam. First, they do reconnaissance. He never attack when he don't know clearly enemy.

Choose place for battle^[10]

In the battle of Rach Gam-Xoai Mut, Nguyễn Huệ chose a section of Mỹ Tho river, from the mouth of the Rạch Gầm river to the mouth of Xoài Mút river as the main battle area to destroy Siamese troops. Rạch Gầm and Xoài Mút are two small rivers, but they are important in the plan of Tây Sơn. The Tây Sơn infantry can be deployed at these two army divide to block Siamese navy on river. At the mouth of the Rạch Gầm river and the mouth of the Xoài Mút river, there are Thới Sơn Island, Hộ island, a convenient place for the Tây Sơn army to secretly deploy artillery ready to hit enemy and pick up groups of Siamese troops landed on shore. Rivers between the islands will be the ambush and departure of the Tây Sơn navy, that it is desirable to draw enemies to a single area, where it is easier to kill them.

Night combat

The main battles were usually conducted in the middle of the night and ended before dawn. Tây Sơn troops spent the day in secret shelter and preparing to strike when the time came. This time around is an advantage in combat.^[11]

Feint ^[12]

In the first pull out to North Vietnam of the Tây Sơn army (in the slogan: "Phù Lê diệt Trịnh" (meaning:"Support Lê dynasty Overthrow Trịnh lords")), the Tây Sơn navy was be sieged by the Trịnh Khải lords's navy on the Vị Hoàng river. With heavy winds blowing, Nguyễn Huệ sent a wooden troops statues on the boat, then to beat the drum, drag the flag, drop the boat to drift away. Trịnh army's commander Đinh Tích Nhưỡng thinking that the Tây Sơn troops came to fight the sloop and he used all his army's gun fire until he know he fail Tây Sơn cunning. Finally, Nguyễn Huệ troops rushed to fight, the Trịnh's army did not resistance, they leave to the boat to escape. The other armies divide of the Trịnh lords were also destroyed, and the Sơn Nam citadel was demolished.

In the time of the defeated of Siam, only after the deployment of the force, Nguyễn Huệ was begin attack for the battle, in order to pull the Siamese to the prepared river to destroy them. The Siamese were despised by contempt, so they falling the trap of Tây Sơn.

At time of war anti Qing force, on December 20, 1788, when the Tây Sơn troops led by Nguyễn Huệ (then Quang Trung emperor) commanded advancing to Tam Điệp mountain, generals Ngô Văn Sở, Ngô Thời Nhiệm and Phan Văn Lân came to the charge. Because they retreat when Qing army attack Thăng Long. Quang Trung smiled:

"Leaving the enemy to avoid their strengh, that's encouraging the general, in addition to making the enemy excited, arrogant, luring the enemy into my weakness as it is. You all not has mistake, they come our country for die, I was have cunning for that."

Not only that, in order to increase the pride of the Qing army, Quang Trung also sent Trần Danh Bình headed the mission of eight people carrying gifts and letters to earnestly ask Sun Shiyi stopping his troops to investigate clearly: "why Tây Sơn had to replace Lê dynasty". The ministry also returned to Sun Shiyi 40 Chinese mans, all man was captured by Đắc Thiện Tống pirates commander. And now, Tây Sơn troops captured him. Indeed, Sun Shiyi was beheaded both Trần Danh Bình, and Đắc Thiện Tống. Take all messengers to prison. At the moment, Quang Trung secretly corrected the general, preparing the battle, deciding a battle to expel Qing from the territory of Đại Việt. On the morning of December 30, before ordering the attack, Quang Trung said:

"I came to when the enemy do not know that they sleeps but me awake, I hit the enemy not in case that I hacked the empty hand, I definitely win..."

Secret factors, the Qing army did not grasp the strength of the Tây Sơn again the habit of contempt, until suddenly attacked they can not fight back.

Ambush and Combined

At Rạch Gầm - Xoài Mút, before the fighting took happen, Nguyễn Huệ sent field observers, firmly grasped the laws of river tide, characteristics of channels, creeks, estuaries and terrains on both sides rivers. Nguyễn Huệ deployed forces in the area were selected before. From Rạch Gầm to Xoài Mút, in addition to choosing the layout of the elite naval forces, Nguyễn Huệ also arranged for the concentration of cannons and army on both sides to ready to fight, when Siamese force enter the battlefield Tây Sơn locked them at face side and back side. Tây Sơn troops also arranged alternately the navy forces in the rivers, creeks and branches combined with infantry, ready to hit the side of the enemy formation on the river and on the ground.^[13]

Fighting speed

In the letter of the clergyman name Le Breton, dated August 2, 1788, he wrote: "So that, Nguyen Hue returned to Phu Xuan in early July. He had to rush his troops so fast that many his soldiers died cause fatigue and sunburn. Even the elephant, horse died too."

At time come to Thăng Long catching killed Vũ Văn Nhậm, from Phú Xuân, Nguyễn Huệ has self-proclaimed infantry, cavalry advancing during day and night. More than 10 days arrived in Thang Long. In the Diary of the Bac Ha Missionary Church sent to the Central Church to report on the strength of the Quang Trung emperor (by French language): "He (Nguyen Hue) moved like a hurricane to the North and only took 10 days, long distance labor has killed many of his elephant and horses, while others take three or four days." With a distance of more than 600 hundred kilometers, travel time is only 10 days; roads are backed by mountains and rivers, the move of such a large army is extraordinary. Horses and elephants also can not stand they dead along the road, above on human ability. About the technology of moving for infantry, Nguyen Hue applied the principle of "collective move continuously day and night, individual rotating resort fresh. Nguyễn Huệ gave his troops three in a row, rotating each other, along the way two people shield one person.^[14]

Surprise attack

Not only did attack speed,^[15] Quang Trung's twin tactic was to attack suddenly, to strike at unbelievable times, preventing their defenses from leading to defeat.^[11]

In the offensive in 1786, while the commander of Trịnh army was out of alert, the Tây Sơn troops began their journey on 28 April lunar month, that 25 May 1786.^[16] In the middle of the fifth lunar month of 1786, Tây Sơn's army lead by Nguyễn Huệ make a surprise attack, the Trịnh army failed to turn up. Hoàng Nghĩa Hồ rescued his troops and was killed.^[17] To capture Hải Vân, Nguyễn Huệ immediately forward troops to Phú Xuân. The second time, the Trịnh troops surprise. Trịnh Tông concentrated in the Tây Long fort, there were 100 war elephants,^[17] totaling 30.000 Trịnh troops on Thăng Long defense. In the critical situation known to be attacked, Trịnh was still not alert, suggesting that the Tây Sơn troops could not advance to Thăng Long quickly.^[18] Eventually, the Trịnh lordship collapsed.

On December 20, 1789, Tây Sơn troops came to Ninh Bình. After reviewing the situation, Quang Trung told his soldiers that in just 10 days, Qing army would be cleaned up. Qing army and Lê Chiêu Thống are in preparation for the Tết holiday, which is not well protected, plus Sun Shiyi's arrogance makes them really surprised. Soon, within six days of the Lunar New Year, the Tây Sơn troops destroyed the Qing army. At 5th Lunar New Year in 1789, Tây Sơn troops entered Thang Long. Sun Shiyi warriors run away, on the road running successively defeated by Tây Sơn soldiers. Finally, Sun Shiyi and Lê Chiêu Thống run away to China.

Take advantage of nominal

Tây Sơn used psychological measures to gain the support of a large number of people, mobilizing many young people to join the army. First of all, in the new stage of setting up the Tây Sơn uprising against Trương Phúc Loan to support Nguyễn lords. So that, they was have belief of lord and many people.

In the later stage, using the name "Phù Lê diệt Trịnh", Nguyễn Huệ talk Nguyễn Hữu Chỉnh moved to the North. Trịnh lords lost on the battlefield, hate by many people in North Vietnam, Trịnh Tông to run out Thang Long, the people touch him and brought to submit Tay Son. Finally, Trịnh Tông suicide.