1. Creation of Xueyantuo Khanate.

Xue Yantuo is a branch of Thiele, and Thiele is another name for Ding Lingren. Tile is home to nine tribes, collectively known as Nine Families of Tile, who have lived in North Sea (Lake Baikal) region for a long time. After Turks became stronger and conquered Tiele, many Tiele tribes joined Turks, but a large number of Tiele tribes continued to remain in Beihai region, maintaining relative tribal independence. The people of Tile are recalcitrant and ungovernable, and have always threatened Turkic rear. To protect this place, Turks placed a northern khan here.

In 603, after more than 20 years of civil war, Turkic Khanate finally split into two parts, Eastern and Western, and its forces were greatly reduced. In 605, under leadership of Yantuo tribe from Tiele Tribal Union, Xue Yanto was founded as a khanate with its capital on Mount Tanhan, and its first khan was Yiuzhen Mohezai Xue-khan. At beginning of creation of Xueyantuo Khanate, it caused a shock in Mobei, to which Yiwu, Gaochang and others belonged. Xueyantuo appointed Tutun here to oversee the country and collect taxes.

By 613, Western Turkic Shekui Khan led troops to defeat Xue Yanto, and both Xue Yanto and Kibi were forced to lose title of Khan, which belonged to Western Turkic. Xue Yantuo died like this. In 628, a war broke out between Yehu Khan of Western Turks and Tseli Khan of Eastern Turks. The Western Turks were defeated, and all tribes east of city of Futu, their khan, surrendered to Eastern Turks. Lead and lead tribe to it appealed to Eastern Turks.

Although Eastern Turks defeated Western Turks, they suffered greatly. Starting from 626, strong snow cataclysms befell Eastern Turks, a large number of livestock perished. To deal with war with Western Turks and Tang Dynasty, Eastern Turks continued to intensify their plunder of surrounding tribes. Yi Nan took opportunity to lead nine families of Ti Le to start a rebellion, and Yugu She, stationed in northern Xinjiang with Eastern Turks, led an army of 100,000 to crush it and was defeated by Yi Nan. The Eastern Turks, one by one, sent Tuoshe and Tuli on a crusade, but they also failed.

Lake Baikal (Khan Sea)

In 628, various ministries of Te Le elected Yi Nan Khan, and Yi Nan immediately sent envoys to Chang'an to make an alliance with Tang dynasty. Tang Taizong Li Shimin canonized Yi Nan as Zhenzhu Wija Khan and presented him with a sword and whip, implying that he Dominates all services in desert. After alliance was successful, Yinan immediately attacked Eastern Turks and occupied Yazhang - Mount Yudujin, where after that Xueyanto Khanate became its capital.

From 629 to 630, Tang Dynasty also sent a large army to north, defeated Tseli Khan, and Turhan surrendered, so Eastern Turkic Khanate officially perished. Subsequently, Tang Dynasty established Shanyu Duhufu in Monan, hometown of Eastern Turks, to govern surrendered Turkic tribes. The vast pastures of Mobei were occupied by Xueyantuo Khanate, which not only restored country, but also grew stronger.

Secondly, change in policy of Tang Dynasty towards Xueyantuo Khanate.

After collapse of Eastern Turkic Khanate, Tang dynasty and Xue Yantuo were still allies. Xue Yantuo continued to pursue a peaceful policy towards Tang Dynasty, and Tang Dynasty continued to support expansion of Xue Yantuo's power. Although Xue Yanto was powerful at that time, his country was not stable, and in west there were remnants of Eastern Turks - Yizhu Chebi Khan occupied Altai Mountains and often disturbed western border of Xue Yanto; after powerful Western Turks were defeated by Xue Yantuo, they considered Xue Yantuo a big enemy.

After several years of development, power of Xueyantuo Khanate grew by leaps and bounds. In 631, Western Turkic Xiehu Khan attacked Xue Yantuo and was defeated by Xue Yantuo. At this time, Xue Yantuo was comparable to Eastern Turks in their heyday, known in history as "Eastern Shiwei, Mount Xijin, Southern Turks, Northern Hanhai, land of Xiongnu in ancient times, with 200,000 victorious warriors." The prosperity of Xueyantuo Khanate caused unrest in Tang dynasty and changed foreign policy of Tang dynasty.

After destruction of Eastern Turks, a large number of Eastern Turks surrendered to Tang Dynasty and were placed by Tang Dynasty in Monan region. The Tang Dynasty treated these Turkic peoples very preferentially, such as giving them generous salaries to high-ranking officials and exempting them from all taxes. This policy contributed to capitulation of Turkic tribes, but seriously increased their own economic burden. With Xueyantuo Khanate prospering, Tang Taizong considered relocating these Eastern Turkic tribes outside Great Wall to re-establish an Eastern Turkic kingdom to support Xueyantuo. In this way, economic burden of Tang Dynasty can be alleviated.

After careful deployment, Emperor Taizong of Tang chose Ashina Simo as a low-status Eastern Turk Restoration Khan. At same time, he is also less bold, which contributes to control. However, Ashina Shimo was worried about being attacked by Xue Yantuo, so he refused to go outside. Tang Taizong then sent envoys to Xue Yantuo for negotiations, demanding that Eastern Turks and Xue Yantuo take Gobi (Daqi) Desert as a frontier and prevent unjustified plunder. In 639, Ashina Shimo officially returned to Monan.

However, Te Le has considered Turks an enemy since ancient times, and Ili and Yinan have always objected to Tang Taizong sending Turks back to desert. However, Tang Taizong's actions quickly escalated desert conflict. In 640, Tang Dynasty conquered Gaochang and invited Xue Yantuo to join forces, but Xue Yantuo refused, showing that relations between two countries had deteriorated and war was imminent.

Third, Xue Yantuo, who became winner, died

In 641, Tang Dynasty recalled famous general Xu Shiji (Xu Maogong) who had guarded Bingzhou for 16 years, so Xue Yantuo Han Yinan took opportunity to attack Ashina Simo with 200,000 men. Ashina Simo was defeated and forced Turks to flee south, asking for help from Tang Dynasty. At this time, Xue Yantuo's army still did not retreat, but stopped to wait and look at front line of Great Wall. General Xue Yantuo generously hoped that Ashina Shimo could not be caught, so he would only have to "climb Great Wall and scold him."

Tang Taizong believed that Xue Yantuo's army was running out when it ran thousands of miles, but after Ashina Simo fled to Great Wall, Xue Yanto still did not retreat, which was a great taboo for military strategists. . So, Zhang Jian, governor of Yingzhou, was first sent to lead an army close to Khitan, to prevent Khitan from participating in chaos, so as not to increase scale of war. Thereafter, Xu Shiji was appointed General Manager of Shuozhou Road to lead a four-pronged army with a total of over 100,000 soldiers in Northern Expedition.

After Tang Dynasty sent troops, Xue Yantuo's army quickly retreated. Led by Ashina Shimo, Tang Dynasty army quickly caught up with Xue Yantuo's main force, and after a fierce battle, Xue Yantuo was defeated.

After this fiasco, Yi Nan suffered greatly. In order to change Tang Chao's attitude, he proposed to Tang Chao. Tang Taizong refused. Tang Taizong refused because although Xue Yantuo was powerful at time, he was born in a low status and could not convince public. However, more than a dozen tribes such as Tonluo and Pugu had stronger powers, and they only temporarily succumbed to Xue Yantuo . If Tang Dynasty and Xue Yantuo were to marry, it would be equivalent to the Tang Dynasty recognizing Xue Yantuo's dominance, and other tribes would "kneel, use them, and obey them more".

Due to failed marriage, political prestige of Xue Yantuo department was undermined, and various departments of Thiele began to rebel. In 645, Xue Yantuo again attacked Eastern Turks. After Tang Dynasty sent troops, Xue Yantuo retreated. At same time, Inan declined alliance's request to join Goguryeo to attack Tang Dynasty, but asked Tang Taizong to jointly attack Goguryeo.

In 645, Yinan died, and his son Bazhuo established himself as Tzeelijuli and lost Xue Shadomi Khan. He suddenly changed his policy towards Tang Dynasty. When Tang Taizong conquered Goguryeo, he attacked border of Tang Dynasty, but was defeated by Tang Dynasty. Later, Tang Taizong decided to suspend Eastern Expedition in Goryeo, but concentrate on fighting Xue Yantuo. In 646, Domi Khan was defeated by army of Tang Dynasty, so he fled to Mobei and was killed by Huihe people. Until Xueyantuo Khanate died.

The reason Tang Taizong wanted to destroy Xueyantuo Khanate was because country's strength continued to grow and this posed a potential threat. However, Xue Yantuo always hated Turks and mostly expressed friendship with Tang Dynasty. Despite this, Tang Dynasty supported its enemies, Turks, and turned to destroying its allies, which ultimately led to a major disaster.

After collapse of Xueyantuo Khanate, Huihe tribe became leader of nine families of Te Le. Emperor Taizong of Tang nominally installed Yanran Dufu at Mobei (later changed to Hanhai and Anbei Dufu), but he did not station a single soldier here, and post of Dufu was only nominally given to Huihe leader. In fact, leader of Uyghurs has long been known as a khan, and Uyghur Khanate was created in essence, while Anbei Capital Protectorate exists only in name. The liquidation of Xueyantuo khanate and rise of Uighur khanate were clearly unexpected for Tang dynasty.

At same time, as Monan of Tang Dynasty tried his best to support remnants of Eastern Turks, it eventually led to restoration of Eastern Turks. During Tang Gaozong period, these Turkic peoples had already risen in rebellion, which caused chaos in northern Xinjiang of Tang Dynasty. In era of Wu Zetian, remnants of Turkic forces finally established "Post-Turkic Khanate" and dominated south of Great Desert. The later Turkic Khanate was more powerful than Eastern Turkic Khanate, leading to massive consumption by Tang Dynasty. After all, Eastern Turks were not destroyed by Uighur Khanate until late Tang Xuanzong.