Han dynasty in Inner Asia

Wars were mainly fought against the nomadic Xiongnu confederation based in the Mongolian Plateau, but also against other states in the Western Regions (especially in the Tarim Basin) like the Saka-ruled (Scythian) Greco-Bactrian Kingdom known to the Chinese as Dayuan.

As a result, the Han dynasty at its height greatly expanded its power into Central Asia, controlling most of present-day Xinjiang and portions of modern Inner Mongolia with the establishment of the Protectorate of the Western Regions and the vassalization of Southern Xiongnu.

The tension fully escalated in 133 BC when the Han army unsuccessfully tried to ambush Xiongnu raiders at Mayi, and retaliatory raids intensified.

Emperor Wu then started deploying newer generations of military commanders and launched several expeditions to control the Ordos Loop, Hexi Corridor and Western Regions, eventually pushing the Xiongnu north beyond the Gobi Desert with a decisive campaign in 119 BC.

For the Xiongnu, the situation deteriorated with each setback, leading to erosion of the chanyu's prestige and dominance, and the subsequent internal power struggles further weakened the confederation, fracturing it into various self-ruling factions.

[5][6] Due to the ensuing war with the Han empire, the Xiongnu were forced to extract more crafts and agricultural foodstuffs from the Tarim Basin urban centres.

[10] The Han empire brought the states of Loulan, Jushi (Turfan), Luntai (Bügür), Dayuan (Ferghana), and Kangju (Soghdiana) into tributary submission between 108 and 101 BC.