Nomadic empire
The Xiongnu were a confederation of nomadic tribes from Central Asia with a ruling class of unknown origin and other subjugated tribes. They lived on the Mongolian Plateau between the 3rd century BC and the 460s AD, their territories including modern day Mongolia, southern Siberia, western Manchuria, and the modern Chinese provinces of Inner Mongolia, Gansu, and Xinjiang. The Xiongnu was the first unified empire of nomadic peoples. Relations between early Chinese dynasties and the Xiongnu were complicated and included military conflict, exchanges of tribute and trade, and marriage treaties. When Emperor Qin Shihuang drove them away from the south of the Yellow River, he built the famous Great Wall to prevent the Xiongnu from coming back.
Yueban
Between 155 and 166, the Xianbei or Syanbi (Ch. , Wade–Giles Hsien-pi, Hsien-pei), a former vassal tribe of the Xiongnu, united under Tian-Shih-huai conducted a series of campaigns against Northern Xiongnu, eventually defeating them and forcing them to flee west, which started a series of Xiongnu migrations (93 CE - circa 380 CE) westward to southern Siberia and Central Asia. (The Xiongnu have often been linked to the Huns that later invaded Europe from the Eurasian steppe, although the link has never been conclusively established. Likewise the Yueban of late antiquity have sometimes been known as the "Central Asian Huns".)