Uyghur Khaganate

In 657 the Western Turkic Khaganate was defeated by the Tang dynasty, after which the Uyghurs defected to the Tang. Prior to this the Uyghurs had already shown an inclination towards alliances with the Tang when they fought with them against the Tibetans and Turks in 627.[10][11]

In 742, the Uyghurs, Karluks, and Basmyls rebelled against the Second Turkic Khaganate.[12]

In 744 the Basmyls captured the Turk capital of Otukan and killed the reigning Özmiş Khagan. Later that year a Uyghur-Karluk alliance formed against the Basmyls and defeated them. Their khagan was killed and the Basmyls ceased to exist as a people. Hostilities between the Uyghurs and Karluks then forced the Karluks to migrate west into Zhetysu and conflict with the Turgesh, whom they defeated and conquered in 766.[13]

The Uyghur khagan's personal name was Qullığ Boyla (Guli Peiluo; Chinese: 骨力裴羅). He took the title Qutlugh Bilge Köl Kaghan "Glorious, wise, mighty kaghan", claiming to be the supreme ruler of all the tribes. He built his capital at Ordu-Baliq. According to Chinese sources, the territory of the Uyghur Empire then reached "on its eastern extremity, the territory of Shiwei, on the west the Altai Mountains, on the south it controlled the Gobi Desert, so it covered the entire territory of the ancient Xiongnu".[14]

In 745 the Uyghurs killed the last khagan of the Göktürks, Báiméikèhán Gǔlǒngfú (白眉可汗 鶻隴匐), and sent his head to the Tang.[15]

Tang Huiyao, vol. 98, listed nine Toquz-Oghuz surname-tribe (姓部 xìngbù); another list of tribes (部落 bùluò) was recorded in Jiu Tangshu & Xin Tangshu. According to Japanese scholars Hashimoto, Katayama, and Senga, each name in the Tang Huiyao list recorded each subtribal surname of each chief; while the other list(s) contained the names of the Toquz Oghuz tribes proper.[16][17] W. B. Henning (1938)[18] linked nine names recorded in the Saka Stäel-Holstein with those recorded by Chinese authors.

In 747, the Qutlugh Bilge Köl Kaghan died, leaving his youngest son, Bayanchur Khan to reign as Khagan El etmish bilge "State settled, wise". After building a number of trading outposts with the Tang, Bayanchur Khan used the profits to construct the capital, Ordu-Baliq, and another city further up the Selenga River, Bai Baliq. The new khagan then embarked on a series of campaigns to bring all the steppe peoples under his banner. During this time the Empire expanded rapidly and brought the Sekiz Oghuz, Kyrgyz, Karluks, Turgesh, Toquz Tatars, Chiks and the remnants of the Basmyls under Uyghur rule.

In 755 An Lushan instigated a rebellion against the Tang dynasty and Emperor Suzong of Tang turned to Bayanchur Khan for assistance in 756. The khagan agreed and ordered his eldest son to provide military service to the Tang emperor. Approximately 4,000 Uyghur horsemen assisted Tang armies in retaking Chang'an and Luoyang in 757. After the battle at Luoyang the Uyghurs looted the city for three days and only stopped after large quantities of silk were extracted. For their aid, the Tang sent 20,000 rolls of silk and bestowed them with honorary titles. In addition the horse trade was fixed at 40 rolls of silk for every horse and Uyghurs were given "guest" status while staying in Tang China.[12][21] The Tang and Uyghurs conducted an exchange marriage. Bayanchur Khan married Princess Ninguo while a Uyghur princess was married to a Tang prince.[15] The Uyghur Khaganate exchanged princesses in marriage with Tang dynasty China in 756 to seal the alliance against An Lushan. The Uyghur Khagan Bayanchur Khan had his daughter Uyghur Princess Pijia (毗伽公主) married to Tang dynasty Chinese Prince Li Chengcai (李承采), Prince of Dunhuang (敦煌王李承采), son of Li Shouli, Prince of Bin. while the Tang dynasty Chinese princess Ninguo married Uyghur Khagan Bayanchur.

In 758, the Uyghurs turned their attentions to the northern Yenisei Kyrgyz. Bayanchur Khan destroyed several of their trading outposts before slaughtering a Kyrgyz army and executing their Khan.[21]

In 759 the Uyghurs attempted to assist the Tang in stamping out the rebels but failed. Bayanchur Khan died and his son Tengri Bögü succeeded him as Khagan Qutlugh Tarkhan sengün.[21]

In 762 Tengri Bögü planned to invade the Tang with 4,000 soldiers but after negotiations switched sides and assisted them in defeating the rebels at Luoyang. After the battle the Uyghurs looted the city. When the people fled to Buddhist temples for protection, the Uyghurs burnt them down, killing over 10,000. For their aid, the Tang was forced to pay 100,000 pieces of silk to get them to leave.[22] During the campaign the khagan encountered Manichaean priests who converted him to Manichaeism. From then on the official religion of the Uyghur Khaganate became Manichaeism.[23]

In 779 Tengri Bögü planned to invade the Tang dynasty based on the advice of his Sogdian courtiers. However, Tengri Bögü's uncle, Tun Bagha Tarkhan, opposed this plan and killed him and "nearly two thousand people from among the kaghan's family, his clique and the Sogdians."[24] Tun Bagha Tarkhan ascended the throne, with the title Alp Qutlugh Bilge ("Victorious, glorious, wise"), and enforced a new set of laws, which he designed to secure the unity of the khaganate. During his reign Manichaeism was suppressed, but his successors restored it as the official religion.[25]

In 780 a group of Uyghurs and Sogdians was killed while leaving Chang'an with tribute. Tun demanded 1,800,000 strings of cash in compensation and the Tang agreed to pay this amount in gold and silk.[26]

In 789 Tun Bagha Tarkhan died and his son, Tolossu, succeeded him. The Karluks took this opportunity to encroach on Uyghur territory and annexed the Futu valley.[27]

In 790 the Uyghurs and Tang forces were defeated by the Tibetans at Ting Prefecture (Beshbalik).[11] Tolossu died and his son, A-ch'o, succeeded him as Qutlugh Bilge.

In 795 Qutlugh Bilge died and the Yaghlakar dynasty came to an end. A general named also called Qutlugh declared himself the new khagan, under the title Tängridä ülüg bulmïsh alp kutlugh ulugh bilgä kaghan ("Greatly born in moon heaven, victorious, glorious, great and wise Kaghan"),[12] founding a new dynasty, the Ediz (Chinese: A-tieh).

In 803 the Uyghurs captured Qocho.[28]

In 808 Qutlugh died and his son Baoyi succeeded him. In the same year the Uyghurs seized Liang Prefecture from the Tibetans.[29]

In 821 Baoyi died and his son Chongde succeeded him. Chongde was considered the last great khagan of the Uyghur Khaganate and bore the title Kün tengride ülüg bulmïsh alp küchlüg bilge ("Greatly born in sun heaven, victorious, strong and wise"). His achievements included improved trade up with the region of Sogdia, and on the battlefield he repulsed a force of invading Tibetans in 821.

In 822 the Uyghurs sent troops to help the Tang in quelling rebels. The Tang refused the offer but had to pay them 70,000 pieces of silk to go home.[26]

In 823 the Tibetan Empire waged war on the Uyghurs.[30]

In 824 Chongde died and was succeeded by a brother, Qasar.

In 832 Qasar was murdered. He was succeeded by the son of Chongde, Hu. In the same year the Tibetan Empire ceased to make war on the Uyghurs.[30]

In 839 Hu was forced to commit suicide and a minister named Kürebir seized the throne with the help of 20,000 Shatuo horsemen from Ordos. In the same year there was a famine and an epidemic, with a particularly severe winter that killed much of the livestock the Uyghur economy was based on.[31]

In 840, one of nine Uyghur ministers, Kulug Bagha, rival of Kurebir, fled to the Yenisei Kyrgyz and invited them to invade from the north. With a force of around 80,000 horsemen, they sacked the Uyghur capital at Ordu-Baliq, razing it to the ground.[1] The Kyrgyz captured the Uyghur Khagan, Kürebir (Hesa), and promptly beheaded him. They went on to destroy other cities throughout the Uyghur empire, burning them to the ground. Öge, son of Baoyi, became khagan of the defeated Uyghur khaganate.

In 841 Öge led the Uyghurs in an invasion of Shaanxi.

In 843 a Tang army led by Shi Xiong attacked the Uyghurs displaced by the fall of their khaganate and slaughtered 10,000 Uyghurs on February 13, 843 at "Kill the Barbarians" Mountain (Shahu).[32][33]

In 847 the penultimate Uyghur khagan, Öge, was killed after having spent his six-year reign fighting the Kyrgyz, the supporters of his rival Ormïzt, a brother of Kürebir, and Tang dynasty troops in Ordos and Shaanxi.[1][23]

Uyghur king from Turfan region attended by servants. Mogao cave 409, 11th-13th century.

Ordu-Baliq, capital of the Uyghur Khaganate (745–840) in Mongolia.

Mural of Uyghur Khagan, VIII century CE

The Yenisei Kyrgyz who replaced the Uyghur Khaganate were unsophisticated and had little interest in running the empire which they had destroyed. They held the territory from Lake Baikal in the east to the Irtysh River in the west and left Kulug Bagha, the Uyghur who defected to them, in charge of the Orkhon Valley. During the reign of Emperor Yizong of Tang (860–873), there were three recorded contacts between the Tang and Kyrgyz, but the nature of their relationship remains unclear. Tang policy makers argued that there was no point in building any relations with the Kyrgyz since the Uyghurs no longer threatened them. The Khitans seized the Orkhon Valley from the Kyrgyz in 890 and no further opposition from the Kyrgyz is recorded.[34][35]

After the fall of the Uyghur Khaganate, the Uyghurs migrated south and established the Ganzhou Uyghur Kingdom in modern Gansu[36] and the Kingdom of Qocho near modern Turpan. The Uyghurs in Qocho converted to Buddhism, and, according to Mahmud al-Kashgari, were "the strongest of the infidels", while the Ganzhou Uyghurs were conquered by the Tangut people in the 1030s.[37] Even so, Kashjgari praised comtemporary Uyghurs as bilingual Turkophones whose Turkic dialect remained "pure" and "most correct" (just like dialects spoken by monolingual Yagmas, and Tuhsis); meanwhile, Kashgari derided other bilingual Turkophones (Qay, Tatars, Basmyls, Chömüls, Yabakus, etc.), for incorporating foreign loanwords and "slurring" in their speeches[38]

In 1209, the Qocho ruler Baurchuk Art Tekin declared his allegiance to Genghis Khan, and the Uyghurs became important civil servants in the later Mongol Empire, which adapted the Old Uyghur alphabet as its official script. According to the New Book of Tang, a third group went to seek refuge among the Karluks.[39] The Karluks, together with other tribes such as the Chigils and Yagmas, later founded the Kara-Khanid Khanate (940–1212). Some historians associate the Karakhanids with the Uyghurs as the Yaghmas were linked to the Toquz Oghuz. Sultan Satuq Bughra Khan, believed to be a Yagma from Artux, converted to Islam in 932 and seized control of Kashgar in 940, giving rise to the new dynasty, known as Karakhanids.[40]