Emperor Wu of Han's northern campaigns against the Xiongnu

Timeline

1. -133Mayi · ShanxiEmperor Wu adopted Wang Hui's plan to ambush the Xiongnu at Mayi; the plan leaked and failed, ending Han-Xiongnu heqin marriages. The two sides entered long-term military confrontation and the Han began actively preparing for northern expeditions.
2. -127–-121Hexi Corridor · GansuWei Qing led forces to recover the Henan region; Huo Qubing campaigned west twice, routing the Xiutu, Hunxie and other Xiongnu tribes and seizing the Hexi Corridor. The Han then established Wuwei, Zhangye, Jiuquan, and Dunhuang commanderies, severing Xiongnu ties with the Western Regions.
3. -119Mobei · Mongolian PlateauWei Qing and Huo Qubing each led 50,000 cavalry deep into Mobei by separate routes; Huo Qubing routed the Xiongnu Left Worthy Prince, sacrificing at Langjuxu and Shan at Guyan, and the Xiongnu fled far, establishing the situation of 'no war south of the desert.'
4. -103–-89Along the Great Wall · ChinaIn later years the Han army still mounted expeditions under Li Guangli; though occasionally defeated, Xiongnu strength had greatly declined. In his late years Emperor Wu issued an edict of self-criticism and pursued recuperation; the northern frontier was basically stabilized, with Han imperial administration and heqin policy running in parallel.