Xiongnu
The Xiongnu () were a confederation of nomadic peoples who, according to ancient Chinese sources, inhabited the eastern Asian Steppe from the 3rd century BC to the late 1st century AD. Chinese sources report that Modu Chanyu, the supreme leader after 209 BC, founded the Xiongnu Empire.
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.