In May of the fourteenth year of the Tang Dynasty (779 AD), Emperor Li Yu of the Tang Dynasty died, and the crown prince Li Shi took the throne as Emperor Dezong of Tang.
Out of courtesy, Emperor Dezong sent emissaries to the Uighur Khanate to pay their respects, and the Uighur Khan was very arrogant and rude.
At this time, he neither received the envoys of the Tang Dynasty nor made a ceremonial condolence for the funeral of Emperor Daizong, but also prepared to take advantage of the Tang Dynasty's national mourning at the instigation of the ninth surname Hu to make a big sneak attack.
The "Nine Surnames Of Hu", that is, the people of the Sui and Tang Dynasties, zhaowu, including Kang, An, Cao, Shi, Mi, He, Huoxun, Pengdi, and Shi Jiuguo, were attached to Hui.
The ninth surname Hu instigated Dengli Khan to oppose Tang, which was opposed by Dun Mohe, the then prime minister and brother of Dengli Khan, who believed that the Tang Dynasty was a great power in the Central Plains, and relations with Hui had always been friendly, and Tang did not do anything unfavorable to Hui, and now the whole country is deep, what if it is not victorious? However, Dengli Khan ignored it and quickly gathered his army in preparation for the southern invasion of the Tang Dynasty.
In fact, as early as the first year of Tang Baoying (762 AD), Dengli Khan had rebelled against the Tang Dynasty.
Let's first understand the history of Huiyi.
This is an ancient ethnic group living in the north of China, whose ancestors can be traced back to the Northern Nomadic people of the Shang and Zhou Dynasties - "Northern Di".
Later, they "followed the world's different names and were given special names according to the place", and in the historical records, they were renamed Ding Zero, Tie Le, Rescue Le, Gao Che, Wu Qi, Yuan Qi, Wei Qi, etc.
When the Xiongnu, Xianbei, and Turks successively dominated the Mongolian steppe, the Hui also submitted to them.
At the end of the fourth century, near Lake Baikal, the Uighurs formed a unified tribe for the first time. After more than two hundred years of development and increasing power, Yu Tianbao Sizai (745 AD) defeated the Eastern Turks and established the Hui Khanate, becoming the fourth steppe overlord after the Xiongnu, Xianbei and Turks.
However, the relationship between Hui and the Tang Dynasty was very special. In the third year of Zhenguan (629), Hui sent emissaries to pay tribute to the Tang Dynasty, and the two sides formally established diplomatic relations. In 646, hui united various ministries and cooperated with the Tang army to destroy the Xueyantuo Khanate, established the Hui khanate, and sent envoys to inform Tang.
In 755, the "Anshi Rebellion" broke out, and due to the insufficient strength of the Tang Dynasty, it had to borrow troops to quell the rebellion. As a neighbor of Tang, Hui Hui did not take the opportunity to expand Tang Province, but at the request of the Tang government, he sent troops three times in 756, 757, and 762 to help Tang quell the rebellion, and successively recovered Chang'an, Luoyang, Hebei and other places.
However, according to the prior agreement with Tang Suzong, only Tang was left with land and shishu, plundered countless gold and women, and also stipulated that Tang silk should be used to buy back silk horses, and the two sides then carried out a long-term silk horse trade.
In addition to helping Tang quell the Anshi Rebellion, Hui Hui also joined forces with the Tang Dynasty's Anxi and Beiting capitals to jointly resist Tubo's attack on the Western Regions, and once again reopened the east-west land transportation that was blocked by Tubo after the Anshi Rebellion.
However, the Anshi Rebellion had not yet been completely quelled, and Tang Xuanzong and Tang Suzong died one after another. Emperor Daizong, who had just ascended the throne, was too busy with funerals and domestic contradictions to focus on countering the rebellion, so he sent envoys to Huiyi, hoping to borrow the Hui army to conquer Shi Chaoyi.
Shi Chaoyi encouraged Dengli Khan to take advantage of the national mourning, the lack of ownership and chaos, and invaded the Tang Dynasty in the south. Under the inducement of Shi Chaoyi and others, Dengli Khan disregarded the friendly relations established with Tang and sent troops to invade Tang.
The Tang Dynasty was shaken, and Emperor Daizong sent Yaozi Ang, Gugu Huai'en and others to lobby Dengli Khan, and finally persuaded Dengli Khan to go south to fight Shi Chaoyi.
Although there was no war between the two sides, it can be seen that the Huidengli Khan was no longer willing to be a vassal state of Tang.
In 779, Dengli Khan thought the time had come, and despite the persuasion of Dun Mohe and the wishes of most of the Uighurs, he wanted to invade the Tang Dynasty in the south.
Seeing that the dissuasion was ineffective, Dun Mohe took advantage of the fact that most of the Uighurs did not want to invade the Tang Dynasty, so he raised an army to kill Dengli Khan and more than 2,000 people with the surname of Hu, and established himself as khan.
After ascending the throne, Dun Mohe Khan sent the Hui dynasty minister Yu Dagan to tang with tang envoys to express his willingness to be a vassal of the Tang Dynasty in order to wait for the edict.
Tang Dezong received the emissary and praised Dun Mohe. In order to favor Hui Hui, the De Sect minister Yuan Xiu was made an emissary of the Tang Dynasty, and Zitun Mohe was made the Khan of Wuyi Success.
Economically, by controlling the main transportation route of the "Silk Road", Hui Hui first exchanged horses for Silk of the Tang Dynasty, and then resold it to India, Persia and other places to make a fortune. In 840 AD, the Uighur Khanate was destroyed by its old enemy, the Ancestors of the Kyrgyz People.
After that, most of the Uighurs migrated westward, one to the west of the Onion Ridge, one to the Hexi Corridor, and one to Turpan, Xinjiang.