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.
Tarim Basin
Around 200 BCE, the Yuezhi were overrun by the Xiongnu. The Xiongnu tried to invade the western region of China, but ultimately failed and lost control of the region to the Chinese. The Han Chinese wrested control of the Tarim Basin from the Xiongnu at the end of the 1st century under the leadership of General Ban Chao (32–102 CE), during the Han-Xiongnu War. The Chinese administered the Tarim Basin as the Protectorate of the Western Regions. The Tarim Basin was later under many foreign rulers, but ruled primary by Turkic, Han, Tibetan, and Mongolic peoples.