Qin's campaign against the Xiongnu
Ordos, Inner Mongolia, ChinaIn 215 BCE, Qin Shi Huangdi ordered General Meng Tian to set out against the Xiongnu tribes in the Ordos region, and establish a frontier region at the loop of the Yellow River. Believing that the Xiongnu were a possible threat, the emperor launched a preemptive strike against the Xiongnu with the intention to expand his empire.