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.
Ordos culture
In Chinese accounts, the Xiongnu first appear at Ordos in the "Yi Zhou Shu" and "Classic of Mountains and Seas" during the Warring States period before it was occupied by the states of Qin and Zhao. It is generally thought to be their homeland; however, when exactly they came to occupy the region is unclear and archaeological finds suggest it might have been much earlier than traditionally thought.