Noin-Ula burial site
Many immigrants lived in the Xiongnu pasturelands, but at first they did not mix with the Xiongnu. To be a Xiongnu, one had to be a member of a clan, born of Xiongnu parents. The newcomers were well off, but were outsiders, and could marry only among themselves, not the Xiongnu. Only later did they intermix, increase in numbers, even created a state that existed from 318 to 350 AD.
Hexi Corridor
During the Han–Xiongnu War, Han China expelled the Xiongnu from the Hexi Corridor in 121 BCE and even drove them from Lop Nur when King Hunye surrendered to Huo Qubing in 121 BCE. The Han acquired a territory stretching from the Hexi Corridor to Lop Nur, thus cutting the Xiongnu off from their Qiang allies. Again, Han forces repelled a joint Xiongnu-Qiang invasion of this northwestern territory in 111 BCE. After 111 BCE, new outposts were established, four of them in the Hexi Corridor, namely Jiuquan, Zhangye, Dunhuang, and Guzang (Wuwei).
From roughly 115–60 BCE, Han forces fought the Xiongnu over control of the oasis city-states in the Tarim Basin. Han was eventually victorious and established the Protectorate of the Western Regions in 60 BCE, which dealt with the region's defense and foreign affairs.