Noin-Ula burial site
The cultural affinity of the Xiongnu was with the peoples of southern Siberia and Central Asia; with the Chinese they exchanged arrows rather than culture: the Xiongnu shot with hand bows, while Chinese employed crossbows, although the Chinese had developed the crossbow from the traditional hand bows. Lev Gumilev elaborates the roots of the Chinese cultural influence found in the Noin-Ula cemetery. The Chinese culture was spread not only by material objects, but also by population admixture. There were populations of Xiongnu that have live under the Han rule as military allies. The Chinese migrated continuously to the steppes, the first big wave arriving in the 3rd century BC during the Tsin dynasty (Pin. "Qin"), when captured Chinese became subjects of the Chanuys, a process repeated during the following centuries. The numerous Han people who deserted and entered Chanuy service (for example, Vey Lüy, Li Lin) also taught the Xiongnu the subtlety of diplomacy and martial arts. Populations of the Xiongnu people also lived under Han rule, mostly serving as military allies under Han command. The capture of populations of Xiongnu by the Han forces in a series of Han versus Hun wars also contributed to additional ethnic integration of the north-central Asian neighbors.
Yuezhi
Gradually the Xiongnu grew stronger and war broke out between them and the Yuezhi. There were at least four wars between the Yuezhi and Xiongnu according to the Chinese accounts. The first war broke out during the reign of the Xiongnu monarch Touman (who died in 209 B.C) who suddenly attacked the Yuezhi. The Yuezhi wanted to kill Modu, the son of the Xiongnu king Touman kept as a hostage to them, but Modu stole a good horse from them and managed to escape to his country. He subsequently killed his father and became ruler of the Xiongnu. It appears that the Xiongnu did not defeat the Yuezhi in this first war. The second war took place in the 7th year of Modu era (203 B.C.). From this war, a large area of the territory originally belonging to the Yuezhi was seized by the Xiongnu and the hegemony of the Yuezhi started to shake. The third war probably was at 176 BC (or shortly earlier) and the Yuezhi were badly defeated.