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.
Five Barbarians
In their wake a power vacuum was left on the Mongolian steppes. The main contenders were the Southern Xiongnu, who inhabited a region to the south of the steppe and had now grown into a group of more than a hundred thousand herdsmen on the Xihe plain, the Xianbei, who lived in the east of the steppe residing on the plains of Manchuria, the Dingling, who originally dwelt on the banks of Lake Baikal and had already commenced trekking south into the steppes before Duo Xian destroyed the Northern Xiongnu, and the Wuhuan, who lived south of the Xianbei and were the weakest of the four.