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.
Proto-Mongols
Between 130-121 BCE, Chinese armies drove the Xiongnu back across the Great Wall, weakening their hold on Gansu as well as on what is now Inner Mongolia, and finally pushed them north of the Gobi into central Mongolia. Following these victories, the Chinese expanded into the areas later known as Manchuria, Mongolia, the Korean Peninsula, and Inner Asia. The Xiongnu, once more turning their attention to the west and the southwest, raided deep into the Amu Darya valley between 73-44 BCE. The descendants of the Yuezhi and their Chinese rulers, however, formed a common front against the Xiongnu and repelled them.