The greatest frontier trouble in ancient Chinese history always came from the steppe empire in the north. The Turks were the strictest border plague of the Tang Dynasty. In particular, the ** Jieli Khan was ambitious and expanded beyond his predecessor. It was he who allowed Tang Taizong and his father to endure the humiliation rarely seen by a Chinese emperor. Therefore, Tang Taizong's spearhead was first pointed at this great trouble.

On the one hand, the steppe empire benefited from the harsh natural environment and backward productivity, so that the local people who survived through natural selection were generally brave and good at war, and their endurance was stronger than that of people in other places. On the other hand, due to the harsh environment and backward productivity, it is difficult to resist severe natural disasters. From the beginning of the first year of Zhenguan (627), the Turks' good luck came to an end, perhaps because the character of Jieli Khan was too poor, so the Turks could not be said to be a one-way disaster. In the first year of Zhenguan, the Turks encountered a rare heavy snowstorm (called the "Great White Disaster" in "Wolf Totem", a similar snowstorm once almost destroyed the prosperous Xiongnu Empire in the Han Dynasty), and a large number of sheep, horses, and people froze to death and starved to death. In the same year, probably resentful of Jieli Khan, the northern Turkic tribes of Tiele (a promising people, whose two tribes later went down in history as Xueyantuo and Hui) fought against the Turks. Interestingly, the leader of the Hui tribe is named "Bodhisattva", and he is really like a god with his help. Legend has it that a few thousand men defeated tens of thousands of Turkic soldiers. The Turki Khan, who led the army, came back and was whipped by the Jieli Khan, which directly led to another event that was extremely unfavorable to the Turks: in the second year of Zhenguan, the Turki Khan surrendered to the Tang Dynasty.

Internal troubles, external troubles, and natural disasters have plunged the Turks, a steppe empire that once made all the surrounding countries tremble, into an unprecedented crisis. The biggest crisis was that the emperor of the Tang Dynasty to the south was Tang Taizong: a Chinese emperor who was full of active offensive spirit. There were not many emperors of this type in future dynasties. In the third year of Zhenguan, the Tang army marched out of the fortress for the first time on a large scale, and the generals were Li Jing, Li Tao, Su Dingfang, etc., none of which were fuel-efficient lamps, and the results can be imagined. The Tang army won the first battle. After being defeated, Jieli Khan retreated north, and at the same time sent people to apologize to the Tang Dynasty and sue for peace. Li Tao and Li Jing discussed and said, don't look at Jieli Khan's request to "raise the country to attach", his tone is so soft that he is dead, in fact, if he is let go, who knows what trouble will be caused next time? As soon as they were in total, they were going to sneak attack, but some people said that they couldn't help it, and our envoys were still there. Li Jing said get out, what are those envoys, if they die, they will die, and it is important to catch Jieli Khan. So Su Dingfang took advantage of the fog to lead the Tang army to attack overnight, cooperated with Li Jing to break the Turkic soldiers, and beheaded more than 10,000 people (note that the number of "beheadings" mentioned in ancient history is not necessarily the number of enemy casualties, some enemies died but the head was not obtained, such as when they were drowned in the river.) And the number of beheadings certainly does not include the number of enemy wounded. So the actual losses of the enemy army far exceeded the number of "decapitations"). Jieli Khan wanted to escape, but was blocked by Li Tao, and the result was ...... Poor man. Jieli Khan was probably the first supreme ruler of the steppe empire to be captured alive by Chinese troops. The Tang army attacked Dingxiang, annihilated the Turks, and captured Jieli Khan alive, which was also the most glorious victory in the Tuobian War in the history of the Tang Dynasty. Jieli Khan was arrested in Chang'an, and Li Yuan, who was still alive as the emperor at the time, was extremely relieved, saying that Lao Tzu gave him a vassal back then, and today I saw him become a prisoner of Lao Tzu's son, which is so cool! In the evening, the emperor, the emperor, the kings, and the concubines went to the Lingyan Pavilion. Li Yuan personally played the pipa, and Li Shimin danced (the Tang Dynasty was really angry...... ), celebrated warmly, and stayed up all night.

** After this attack, his troops were moved south by the Tang Dynasty and led by the captive Turkic general Ashnasimo, who surrendered. **'s hometown was occupied by Xue Yantuo, one of the Tiele tribes. The wall fell down and everyone pushed it, ** is a plucked phoenix is not as good as a chicken. Xue Yantuo attacked Ashina Simo many times, and Ashina Simo complained to the Tang Dynasty. When Tang Chao asked, Xue Yantuo explained that I think how powerful the Turks harmed your Tang Dynasty at the beginning, and I am helping you out now. The question is: now that the Turks have returned to the Tang Dynasty, you have to look at the owner to beat the dog, right? Tang Taizong was very dissatisfied with Xue Yantuo and laid the groundwork for the future destruction of Xue Yantuo.

The Turks were the biggest frontier problem of the Tang Dynasty, and it became much easier to establish a single-level world as one of the two superpowers that coexisted at the same time. But things in the Tang Dynasty were often like this, that is, pressing the gourd and scooping. Just after the pacification of the Turks, eight years after Zhenguan, a country destined to make the second half of the Tang Dynasty unpeaceful began to rise. That is Tibet. After Songtsen Gampo became the Zampu of Tibet, he was good at expansion and soon dealt a severe blow to Tuyuhun, which was located in the area of present-day Qinghai. After defeating Tuyuhun, Songtsen Gampo was full of ambition and took advantage of the national situation to ask the Tang Dynasty for peace. (Harmony in the Han Dynasty was humiliating in China, but in the Tang Dynasty, it was often used as a reward and honor for surrounding vassals, and the Tang government often used the rejection of harmony to express dissatisfaction and punishment to the vassals.) To use an inappropriate analogy, the harmony of the Tang Dynasty is somewhat similar to the gift of giant pandas to foreign countries today. Tang Taizong and Tubo didn't have much contact, and obviously they weren't close enough to be close enough to be close to Cheng Dù, so they naturally refused. Now Songtsen Gampo is gone. Who is Lao Tzu? The fiercest Zampu in the history of Tibet! Proposing to you is to give you face, and you are not ashamed to give back? Tubo immediately sent troops, defeated the Tang army's border guards, entered the siege of Songzhou, and said that he would not be allowed to fight with his relatives. The momentum of Tibet cannot be said not to be scary, but ...... Who let him meet Tang Taizong? Tang Taizong is not the kind of weak ruler who can let you dominate a woman by putting a few cannons on the border. So another famous general of the Tang Dynasty, Hou Junji, was ordered to lead troops to repair the arrogant Tubo. Hou Jun Jitong Guò attacked and defeated the Tubo army at night, beheading more than 1,000 people. After the Tibetan army retreated, Songtsen Gampo did what Jieli Khan had also done: he sent an envoy to apologize for his sins and sue for peace. But he did not give up the request for peace and pro. Probably moved by his persistence, his request was finally met after 7 years. In the fifteenth year of Zhenguan, Princess Wencheng entered Tibet.

In the second year after the defeat of Tubo, some party members attached to the Tang Dynasty rebelled against the Tang Dynasty and returned to Tuyuhun. Tang Jun reacted quickly, and the leaders were all masters who could be demoralized as soon as they heard their names - Li Jing, Xue Wanche, and Hou Junji. After the defeat of Fu Yunchu at the hands of Li Daozong, the Tuyuhun Khan made a move that the nomads regarded as a beast of the flood: burning the grassland (the "Wolf Totem" also says that only the Han set fire to the grassland...... ）。 Fu Yun used this strong wall to clear the wilderness to try to dispel the idea of the Tang army's desert expedition. Li Jing adopted Hou Junji's opinion: one day of the enemy, several generations of trouble, the offender of the Tang Dynasty, although far away will be punished, surprise, long-distance attack. The Tang army attacked in the north and south, and the southern route was led by Hou Junji and Li Daozong, and went deep into the no-man's land for more than 2,000 miles, walking through the dangerous situation where frost could fall in midsummer. Fu Yun escaped well and prepared to flee to Khotan. The Tang army went on another expedition, and there was a lack of water on the way, so they stabbed their horses and drank blood, and finally broke through Fu Yun's tooth tent, and Fu Yun left his wife and children to slip away, and was soon killed by his subordinates in the desert. Tuyuhun was thus included in the Tang Dynasty's sphere of influence.

The fifteenth year of Zhenguan was an important year for the Tang Dynasty to pacify the western frontier during the Zhenguan period. Three major events took place this year. The first is that Princess Wencheng entered Tibet. The second is the defeat of the Western Turks by the Don army. The Western Turkic Dulu Khan and the Crossbow lost their surnames. The Turkic people are really good at fighting. The whole history of the Turks is almost a history of infighting. The Dulu Khan defeated his rivals, and in a moment of smugness, began to invade the Tang Dynasty. This time, it was Guo Xiaoke, who led his troops to repel the Turkic soldiers, and immediately launched a counterattack, beheading more than 1,000 people. The Turks once again had civil strife, "many people perished, and their countries were in turmoil." The third thing is that the Tang army dealt a heavy blow to Xue Yantuo and prepared for its destruction in the future. This time, it was Xue Yantuo who attacked Ashina Simo, and Ashina Simo asked the Tang Dynasty for help. The Tang Dynasty couldn't bear it anymore and sent Li Tao and Xue Wanche to lead troops to help. Xue Yantuo's army fought in a very strange way, five people in a team, one of them led the horse, and the other four fought on foot, won the horse pursuit, and then got on the horse and fled after losing. Do you have to get off your horse and fight? ）。 Li Tao resisted Xue Yantuo's army head-on, and Xue Wanche led the cavalry to first defeat the people leading the horses behind Xue Yantuo's formation. Seeing that the horses were robbed, Xue Yantuo's army "lost their horses and didn't know what to do", and was killed by the Tang army and "ambushed in the wild". In this battle, the Tang army beheaded more than 3,000 people and captured 15,000 horses. According to the rules, Yi Nan, the leader of Xue Yantuo, sent a messenger to ask for guilt and ask for peace.