Han dynasty
To the north of China proper, the nomadic Xiongnu chieftain Modu Chanyu (r. 209–174 BC) conquered various tribes inhabiting the eastern portion of the Eurasian Steppe. By the end of his reign, he controlled Manchuria, Mongolia, and the Tarim Basin, subjugating over twenty states east of Samarkand. Emperor Gaozu was troubled about the abundant Han-manufactured iron weapons traded to the Xiongnu along the northern borders, and he established a trade embargo against the group. In retaliation, the Xiongnu invaded what is now Shanxi province, where they defeated the Han forces at Baideng in 200 BC. After negotiations, the "heqin" agreement in 198 BC nominally held the leaders of the Xiongnu and the Han as equal partners in a royal marriage alliance, but the Han were forced to send large amounts of tribute items such as silk clothes, food, and wine to the Xiongnu.
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.