After the destruction of the Uighur Khanate in 840, some tribes migrated west to Gansu, where they established the Uighur kingdom of Ganzhou (later, in 1026 to be conquered by the Tangut. The Yughur nationality in the vicinity of Jiuquan, Gansu province, are their present-day descendants). Another important branch (fifteen tribes) migrated westward to the area of Beshbalïk (in Chinese called Beiting; its ruins are at Hubaozi in Jimsar county, Xinjiang Uighur Autonomous Region) north of the T’ien Shan mountain range, crossed the T’ien Shan southward and occupied the Turfan basin where the Uighur kingdom of Kocho was established (c. 860–1284). Shortly afterwards the Uighurs expanded their power to include the Yanqi (Argi, Karashahr) and Qiuci (Kuci, Kuchar) areas. Historical records
concerning the Uighur kingdom of Kocho are very sparse. The Chinese records are fragmentary because the chaotic situation in China during the period of the Five Dynasties or Ten Kingdoms (907–60), and the weak government of the Sung dynasty (960–1279), did not allow much attention to be paid to the Western Regions. Arab and Persian sources had little interest in a land that was not yet Islamic and the records written in Uighur were mostly destroyed after the introduction of Islam into the Tarim basin.
The Uighur name ‘Kocho’, originating from the Chinese ‘Gaochang’, refers to the city as well as to the area. The ruins of the ancient city of Gaochang, with its imposing walls, stand 40 km east of the Turfan county administrative centre. The Turfan region, located in the north-eastern part of the Tarim basin, was an important line of communication between East and West and had since ancient times been a key post on the Silk Route.
History of Civilizations of Central Asia: The Age of Achievement: A.D. 750 to the End of the Fifteenth Century, Part One: The Historical, Social and Economic Setting
