Because it is located on the Silk Road, the xiyu have been important since at least the 3rd century BC.
The Han–Xiongnu War (ended 89 AD) was fought there.
In the 7th century, the Tang campaign against the Western Regions led to Chinese control of the region.
This was especially true during the Mongol Empire.
- Tikhvinskiĭ, Sergeĭ Leonidovich and Leonard Sergeevich Perelomov (1981). China and her neighbours, from ancient times to the Middle Ages: a collection of essays. Progress Publishers. p. 124.