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.
Liu Fei, Prince of Jiangdu
In 129 BCE, during the reign of Emperor Wu, the Xiongnu nomadic empire attacked the Han. Liu Fei volunteered to join the counterattack against Xiongnu, but his request was denied by the emperor.