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.
Xiongnu
Lajos Ligeti was the first to suggest that the Xiongnu spoke a Yeniseian language. In the early 1960s Edwin Pulleyblank was the first to expand upon this idea with credible evidence. In 2000, Alexander Vovin reanalyzed Pulleyblank's argument and found further support for it by utilizing the most recent reconstruction of Old Chinese phonology by Starostin and Baxter and a single Chinese transcription of a sentence in the language of the Jie people, a member tribe of the Xiongnu Confederacy. Previous Turkic interpretations of the aforementioned sentence do not match the Chinese translation as precisely as using Yeniseian grammar. Pulleybank and D. N. Keightley asserted that the Xiongnu titles "were originally Siberian words but were later borrowed by the Turkic and Mongolic peoples". The Xiongnu language gave to the later Turkic and Mongolian empires a number of important culture words including Turkish tängri, Mongolian tenggeri, was originally the Xiongnu word for “heaven”, chengli (tháːŋ-wrə́j). Titles such as tarqan and tegin and kaghan were also inherited from the Xiongnu language.