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
However, after the sudden death of Qin Shi Huang, the ensuing political corruption and chaos during the short reign of Qin Er Shi would lead to various anti-Qin rebellions, eventually bring about the collapse of the Qin Dynasty. A massive civil war then erupted between various reinstated states, with Liu Bang eventually victorious to establish the Han Dynasty. During the transitional years between Qin and Han, while the Chinese were mainly focused towards the interior of their nation, the Xiongnu took the opportunity to retake the territory north of the wall. The Xiongnu frequently led incursions to the Han frontier and had considerable political influence over the border regions. In response, Emperor Gaozu led a Han army against the Xiongnu in 200 BC, pursuing them as far as Pingcheng (present-day Datong, Shanxi) before being ambushed by Modu Chanyu's cavalry. His encampment was encircled by the Xiongnu, but Emperor Gaozu escaped after seven days. After realizing that a military solution was not feasible for the time being, Emperor Gaozu sent Liu Jing to negotiate peace with Modu Chanyu. In 198 BC, a marriage alliance was concluded between the Han and the Xiongnu, but this proved far from effective as the incursions in the frontier regions continued.