Zhang Qian
In the spring of 121 BC, Huo Qubing led a force of 10,000 cavalry and killed 8,960 Xiongnu west of the Yanzhi Mountains (in modern Gansu). In the summer he and several others marched west. Huo made it as far as the Qilian Mountains south of Jiuquan, killing and capturing 33,000 Xiongnu. The Xiongnu also invaded Yanmen Commandery so Li Guang and Zhang Qian gave chase. Li Guang was suddenly surrounded by 40,000 Xiongnu under the Wise King (Tuqi) of the Left but was able to hold off repeated attacks for two days until Zhang Qian arrived and the Xiongnu retreated. Zhang Qian was demoted to commoner status for arriving late.