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.
Han–Xiongnu War
In 67 BC, the Han empire gained absolute control over the Turfan Depression after inflicting a significant defeat to the Xiongnu. During the former Xiongnu rule of the Western Regions, the area was under the jurisdiction of the Rizhu King (日逐王) with the office "Commandant in
Charge of Slaves". However, in 60 BC, the Rizhu King surrendered to Protector General Zheng Ji. Afterwards (60 BC), the Han imperial court established the Protectorate of the Western Regions. The Han empire, now in absolute control of the Western Regions, placed it under the jurisdiction of its Protector General. As its dominance of the area was established, the Han were effectively controlling the trade and shaping the early history of what would be known as the Silk Road.