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.
Han–Xiongnu War
The first half of the 1st century BC witnessed several succession crises for the Xiongnu leadership, allowing the Han empire to reaffirm its control over the Western Regions. Huduershi Chanyu was succeeded by his son Punu (蒲奴) in 46 AD, thus breaking the late Huhanye's orders that only a Xiongnu ruler's brother was a valid successor. Bi (比), the Rizhu King of the Right and Huduershi's nephew, was outraged and was declared a rival Chanyu by eight southern Xiongnu tribes in 48 AD. The Xiongnu confederation fell apart in the Northern Xiongnu and Southern Xiongnu, and Bi submitted to the reign of the Han empire in 50 AD. The Han took control of the Southern Xiongnu under Bi, which had 30–40 thousand troops and a population of roughly twice or thrice the size.