Gaochang[1] (Chinese: 高昌; pinyin: Gāochāng; Old Uyghur: Qocho), also called Khocho,[2] Karakhoja, Qara-hoja, Kara-Khoja or Karahoja (قاراغوجا in Uyghur), was an ancient oasis city on the northern rim of the inhospitable Taklamakan Desert in present-day Sanbu Township, Xinjiang, China.

Gaochang is considered in some sources to have been a "Chinese colony",[4][5] that is, it was located in a region otherwise occupied at the time by West Eurasian peoples.

In 327, the Gaochang Commandery (jùn) was created by the Former Liang under the Han Chinese ruler Zhang Jun.

[10] After the fall of the Western Jin dynasty, Northern China split into multiple states, including the Central Asian oases.

[4][20] and appointed a Han from Dunhuang, named Zhang Mengming (張孟明), as his own vassal King of Gaochang.

In 501, Ma Ru himself was overthrown and killed, and the people of Gaochang appointed Qu Jia (麴嘉) of Jincheng (in Gansu) as their king, forming the Qushi Kingdom (麹氏王国, 501-640 CE).

Qu Jia hailed from the Zhong district of Jincheng commandery (金城, roughly corresponding to modern day Lanzhou, Gansu)[20] Qu Jia at first pledged allegiance to the Rouran, but the Rouran khaghan was soon killed by the Gaoche and he had to submit to Gaoche overlordship.

[23] While the material civilization of Kucha to its west in this period remained chiefly Indo-Iranian in character, in Gaochang it gradually merged into the Tang aesthetics.

[31][32] During this period, Gaochang's administration, language, city planning, and Confucian society was so heavily dominated by Chinese models that it was known in Sogdian as "Chinatown", a usage which continued as late as the tenth-century Persian geography Ḥudūd al-‘Ālam.

[24] Gaochang was annexed by the Chinese Tang dynasty and turned into a sub-prefecture of Xizhou (西州)[34][35] and the seat of government of Anxi (安西).

[36] Gaochang was populated by Han people and Shanxi (Hedong) was the original home of the royal family at the time of the Tang dynasty's annexation.

[38] The Tang dynasty became greatly weakened due to the An Lushan Rebellion and in 755, the Chinese were forced to pull back their soldiers from the region.

The Buddhist Uyghur kings, who called themselves idiquts, retained their nomadic lifestyle, residing in Qocho during the winter, but moved to the cooler Bishbalik near Urumchi in the summer.

As far south as Quanzhou, preponderance of Gaochang Uyghur in Church of the East inscriptions of the Yuan period attests to their importance in the Christian community there.