Xiongnu
Full-scale war broke out in autumn 129 BC, when 40,000 Chinese cavalry made a surprise attack on the Xiongnu at the border markets. In 127 BC, the Han general Wei Qing retook the Ordos. In 121 BC, the Xiongnu suffered another setback when Huo Qubing led a force of light cavalry westward out of Longxi and within six days fought his way through five Xiongnu kingdoms. The Xiongnu Hunye king was forced to surrender with 40,000 men. In 119 BC both Huo and Wei, each leading 50,000 cavalrymen and 100,000 footsoldiers (in order to keep up with the mobility of the Xiongnu, many of the non-cavalry Han soldiers were mobile infantrymen who traveled on horseback but fought on foot), and advancing along different routes, forced the "chanyu" and his court to flee north of the Gobi Desert. Major logistical difficulties limited the duration and long-term continuation of these campaigns. According to the analysis of Yan You (嚴尤), the difficulties were twofold. Firstly there was the problem of supplying food across long distances. Secondly, the weather in the northern Xiongnu lands was difficult for Han soldiers, who could never carry enough fuel. According to official reports, the Xiongnu lost 80,000 to 90,000 men, and out of the 140,000 horses the Han forces had brought into the desert, fewer than 30,000 returned to China.
Prehistory of Siberia
Sure statements are possible only since the first millennium BC, when neighbouring literate cultures came into contact with the people of the steppe. In the steppes north of the Black Sea and east of the Caspian Sea, Greek, Assyrian and Persian sources attest to horse nomads, which can be identified as speakers of Iranian languages. The first reports from ancient China of the nomads north of China date from the same period Along with various unidentified groups from Shang and Zhou dynasty texts, the Xiongnu are worthy of mention. Based on personal names and titles transmitted by the Chinese sources, different scholars have attempted to identify the language of the Xiongnu as an early Turkic language, a proto-Mongolic language or a Yeniseian language. At the beginning of the early Middle Ages, the Iranian peoples disappeared and in their place Turkic peoples expanded across the region between the eastern edge of Europe and northeastern Siberia. In the areas to the north of the Asiatic steppes, speakers of Uralic and Palaeo-Siberian languages are suspected to have been settled; in the Middle Ages, Turkic peoples appear here as well, but their prehistoric extent is not clear.