Emperor Taizong of Tang
His personal name is Li Shimin.
He was the second emperor of the Tang Dynasty, and he made great contributions to the establishment and prosperity of the Tang Dynasty, and is known as one of the greatest emperors in Chinese history.
East Turkic invasion
At the beginning of emperor Taizong of tang’s reign（personal name Li Shimin）, the northwest frontier of Tang Dynasty was very unstable.
The main threat to the Tang dynasty at that time was Eastern Turks.
When the Tang Dynasty was established, in order to concentrate on dealing with the Sui Dynasty, a compromise was adopted to the Eastern Turks.
However, the Eastern Turks frequently invaded the Tang border.
Less than 20 days after li Shimin ascended the throne, the Eastern Turks jie li Khan led more than 100,000 troops to the wei River, just 20 km from Chang ‘an, the capital of the Tang Dynasty.
Jie li Khan thought li Shimin just came to the throne, will certainly surrender to him, he first sent an messenger into Chang ‘an to see li Shimin, threatening a million army, immediately come.
After hearing what the messenger said, li Shimin seized the emissary.
He first arranged for the Tang army, then personally took six generals, riding to the Wei River to negotiate.
When Jie li heard that the messenger had been detained, he was afraid.
Li Shimin said to Jie li across the Wei river, “we have already made an agreement, why do you break faith and lead an army to invade?”
Jie li had nothing to say and said he was willing to negotiate..
At the end of two days the parties made a covenant.
After this, li Shimin stepped up his training and summoned hundreds of soldiers every day to practice bows and arrows in front of the palace.
He said to his men: “Foreign invasions are a common occurrence and are not to be feared. From now on, I do the teacher, teach you bow and arrow; In time of war I will be the general to lead you against the enemy.”
Encouraged by him, the soldiers devoted themselves to training.
The next year, there was a heavy snow in the north. Many livestock died in Eastern Turks.
At the same time, jie li intensified his oppression of the other tribes, causing them to rebel again.
He sends his cousin Tuli to crush them, But he failed.
Tuli fled back, was given a beating by Jie li. Then he surrendered to the Tang Dynasty.
Li Shimin‘s attack
Li Shimin seized this opportunity and sent Li Jing, Xu Shiji and other generals to lead the army of more than 100000 to attack the eastern Turks.
Li Jing was a famous strategist in the early Tang Dynasty. He was proficient in the art of war.
In 630, Li Jing himself led 3, 000 elite cavalry, set out from Mayi and approached the East Turkic camp.
Jie li was shocked to find that the army of the Tang suddenly appeared.
The soldiers also said in panic: “It must be the Tang dynasty to mobilize the whole country army, otherwise, how dare Li Jing go deep alone?”
Before the Tang army could launch an attack, the East Turkic soldiers were in chaos.
Li Jing and sent spies into the east Turkistan internal and let a general trusted by Jie li surrender to the Tang Dynasty.
Seeing that the situation was bad, Jie li stole away.
Jie li fled to the north of Yinshan, fearing that the Tang army would continue to pursue him. He sent an emissary to Chang ‘an.
Li Shimin side sent Tang Jian to appease, on the other hand ordered Li Jing to lead the army to look at jie li action.
Jie Li Khan’s peace was in fact only a delaying tactic. When he saw Tang Jian coming, he thought That Li Shimin had fallen into his trap.
In the evening of that day, Li Jing and Xu Shiji led the Tang army to Yinshan.
When the Eastern Turkic outpost found the Tang army, the Tang army left the Camp of Jie li only 3.5 km.
Jie li know that tang army came, hurry to find Tang Jian.
However, Tang Jian had already returned to the Tang camp.
In the ensuing war, the East Turkic army was defeated by the Tang army.
This victory raised Li Shimin’s prestige among all the nationalities in northwest China.
In that year, the leaders of all the nationalities came to Chang ‘an together and supported Li Shimin as their common leader, respectfully calling him “Tian Khan”.