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.
Han–Xiongnu War
During the spring of 123 BC, General Wei Qing set off to Mongolia with an army to attack the Xiongnu; they marched back victorious to Dingxiang. Two months later, the Han army advanced towards the Xiongnu again, but this time the Xiongnu were prepared for the invasion by the Han forces. However, hereafter, due to the military expeditions that the Han empire undertook, the Xiongnu moved their capital and retreated to the far northern regions of the Gobi Desert.