Li Mu 李牧, personal name Zuo 繓, was a general of the state of Zhao 趙 during the Warring States period 戰國 (5th cent.-221 BCE). In 265, he obtained the order to protect the northwestern commanderies of Yanshan 雁山 and Daijun 代郡 against raids by the Xiongnu 匈奴 (or Eastern Hu 東胡) tribes. Li's strategy was first only to defend, and not to try to attack or pursue the cavalry of his enemies, but after some time he went over to offensive, and several times destroyed large Xiongnu units. The tribes were so weakened that the northern frontier of Zhao was secure for more than ten years.
In 243, Li Mu took over command in the war gainst the state of Yan 燕 and conquered Wusui 武遂 and Fangcheng 方城. When general Lian Po 廉頗 offered his service to the king of Wei 魏, Hu Zhe 扈輒 (d. 233) died on the battlefield, and Ju Xin 劇辛 defected to Yan, Li Mu was the sole general in the service of Zhao, and had to arrange everything for resistance against the army of Qin 秦.
In 233, the army of Qin attacked the towns of Chili 赤麗 and Xuan'an 宣安. Li Mu erected a fortified camp at Feidi 肥地 (today's Gaocheng 藁城, Hebei) and waited that the Qin general Huan Yi 桓齮 (d. 227) divided his army to attack one of the divisions. The plan succeeded, and Li Mu defeated the Qin army at Yi'an 宜安 (close to Shijiazhuang 石家莊, Hebei). He was rewarded with the title of Marquis of Wu'an 武安君. A year later, he defeated the Qin army once more at Fanwu 番吾 (Pingshan 平山東, Hebei).
Only in 230, Qin decided to launch a large campaign against the alliance of the six states. It began with an attack on Zhao under the command of Wang Jian 王翦. Li Mu and Sima Shang 司馬尚 assumed a similar strategy like three years before and awaited the arrival of the Qin army. Yet Wang Jian infiltrated the government of Zhao and succeeded by having two ministers, Guo Kai 郭開, and Han Cang 韓倉, intervene and have the two generals replaced by Zhao Cong 趙蔥 and Yan Ju 顏聚. Li Mu was killed or commmitted suicide just after his dismissal. Not long thereafter, Handan 邯鄲 (today in Hebei), the capital of Zhao, fell into the hands of Qin.