The Xiongnu (Chinese: 匈奴, [ɕjʊ́ŋ.nǔ]) were a tribal confederation of nomadic peoples who, according to ancient Chinese sources, inhabited the eastern Eurasian Steppe from the 3rd century BC to the late 1st century AD. Modu Chanyu, the supreme leader after 209 BC, founded the Xiongnu Empire.
After overthrowing their previous overlords, the Yuezhi, the Xiongnu became the dominant power on the steppes of East Asia, centred on the Mongolian Plateau. The Xiongnu were also active in areas now part of Siberia, Inner Mongolia, Gansu and Xinjiang. Their relations with the Chinese dynasties to the south-east were complex—alternating between various periods of peace, war, and subjugation. Ultimately, the Xiongnu were defeated by the Han dynasty in a centuries-long conflict, which led to the confederation splitting in two, and forcible resettlement of large numbers of Xiongnu within Han borders. During the Sixteen Kingdoms era, listed as one of the "Five Barbarians", their descendants founded the dynastic states of Han-Zhao, Northern Liang and Helian Xia and during the Northern and Southern dynasties founded Northern Zhou (founded by members of the Yuwen tribe of Xiongnu origin) in northern China.