Between 130-121 BCE, Chinese armies drove the Xiongnu back across the Great Wall, weakening their hold on Gansu as well as on what is now Inner Mongolia, and finally pushed them north of the Gobi into central Mongolia.
The identity of the ethnic core of Xiongnu has been a subject of varied hypotheses and some scholars, including A. Luvsandendev, Bernát Munkácsy, Henry Hoyle Howorth, Bolor Erike,[REF] Alexey Okladnikov, Peter Simon Pallas, Isaac Jacob Schmidt, Hyacinth and Byambyn Rinchen,[REF] insisted on a proto-Mongolian origin.