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.
Qin's campaign against the Xiongnu
In 215 BC, Qin Shi Huang ordered General Meng Tian to set out against the Xiongnu tribes in the Ordos region, and establish a frontier region at the loop of the Yellow River. Believing that the Xiongnu were a possible threat, the emperor launched a preemptive strike against the Xiongnu with the intention to expand his empire.