The uygur flag

After 210 B.C., the Uyghurs played important roles in the Hun (220 B.C. - 386 A.D.), Tabgach (Toba) (386-554 A.D.), and Kok Turk (552-744 A.D.) empires which were established in Central Asia

After the fall of the Kok-Turk Empire in Central Asia, the Uyghurs established their first true state in 744, with the city of Karabalgasun, on the banks of the Orkhun River, as its capital.

The founder of this Uyghur state was Kutluk Bilge Kul Khagan (King or Ruler). In 747, he was succeeded by his son Moyunchur, a powerful leader who subdued other Turkic clans, consolidated the monarchy, and extended his rule in the north to Lake Baikal, in the east to Gansu and in the southwest to India. 

It so happened that just as the Uyghurs became united and strong, the Chinese Tang Dynasty under Hsuan-tsung (Xuanzong) (712-756 A.D.) was undergoing a sharp decline. In 751, a Chinese army was disastrously defeated at the battle of Talas River by the Arabs, Tibetans, and the Uyghurs. In the same year, a Chinese invasion of the Nan-chao (Nanzhao) to the southeast was thwarted with appalling losses to the Chinese; and a Chinese force under An Lu Shan was defeated by the Khitan (Qidan) in the northeast. These disasters were but the prelude to a much more fearful
catastrophe - the rebellion of the former trusted minister An Lu Shan which broke out in 755 A.D.

It was under these circumstances that the Uyghurs were invited by Su-tsung (Suzong), the Hsuan-tsung's (Xuanzong) successor, to send armies to help the Chinese. In this event, the Uyghur forces played a key role in the recapture of both Chang-An (Chang'an) and Lo-yang (Luoyang) in 757. The Uyghurs did not hesitate to exploit the Tang Dynastic debt owed them, by acts of appalling pillage. The Chinese emperor agreed to pay 20,000 rolls of silk as a tribute annually to the Uyghurs and granted the Uyghur Khagan one of his daughters in marriage. 10 She was the first of three princesses of the Chinese imperial family to become a Uyghur khatun (wife) in the period 744-840 A.D.

Moyunchur Khagan died in 759 and was succeeded by his son Bugu Khagan. During his reign, the Uyghurs reached the apex of their power. They began with China, which engaged in forced trade of Uyghur horses for Chinese silk - an exchange which was noted frequently in Chinese sources before 829.

In 762 Bugu Khagan sent to the Middle Kingdom where he helped the Tang Dynasty in the final battles against the rebellion which had racked it for so long.

In 779, Bugu Khagan was killed by his first cousin and chief minister Baga Tarkan. Bugu Khagan's Sogdian allies and advisors had wanted him to take advantage of the death in 779 of Emperor Tai-tsung (Taizong) and the state mourning involved in it, to undertake an invasion of China. Bugu Khagan agreed to do this. His first cousin Baga Tarkan opposed the plan; and when he saw the tide turning against him, murdered Bugu Khagan and set himself on the throne. Baga Tarkan, believed at this stage China could have been conquered by the Uyghurs. But he did not believe that Uyghurs would be able to preserve their cultural identity if they once conquered China, a vast and populous country even then.

After the death of Baga Tarkan in 789 and specially after that of his successor, Kulug Bilge Khagan in 790, Uyghur power and prestige declined

In 795, the rule of the Uyghur state passed to another clan. Under this new clan the Uyghurs became more and more steeped in religion, which softened them and planted seeds of advanced culture which characterized the Uyghurs of later ages.

The most important ruler of this clan was Kutluk Bilge Khagan, whose successful military exploits, both before and during his reign, are reported in the Karabalgasun inscriptions.  He did not succeed , however, in restoring the Uyghur empire to its former power.

With Kutluk Bilge Khagan's death in 805, the forces of disintegration of the Uyghur state gathered momentum. War broke out abroad with the powerful Kyrgyz neighbors to the north; while at home, court intrigue eroded the power of the royal family; rebellions broke out, and, to add to everything, a bad season and severe winter in 839 killed much of the livestock upon which the Uyghur economy was so dependent. In 840, the Kyrgyz, invited by a rebel chief, attacked the
tottering state, killed the Khagan, and took the capital.

This first part of Uyghur political history shows the Uyghurs as the protectors of the Chinese empire for almost a century. On the other hand, the relationship was not really a friendly one. There was abiding resentment on the Chinese side. The reason was that the Middle Kingdom was obliged to be protected by a "barbarian" people. The Uyghurs, for their part, never gave the Chinese the respect which the latter would have liked.

After the fall of the first Uyghur empire, a group of Uyghurs emigrated to the west banks of the Yellow River in Kansu (Gansu); a second group emigrated via Yetti Su to the Southern part of Khan Tengri or Tianshan in Eastern Turkestan; the third and the largest group emigrated to the northern part of Khan Tengri where their ancestors are still living.