Zhao killed its best general on a bribe — and lost the kingdom three months later

By the late third century BC, the state of Zhao was the last serious barrier between Qin and the conquest of China. Its greatest general, Li Mu, had spent years on the northern frontier pretending weakness while building a strike force; when the Xiongnu finally committed, he destroyed over 100,000 of their cavalry in a single ambush and kept the border quiet for a decade. Qin's generals then discovered that he was just as formidable in the south: at Yian in 234 BC he routed a Qin army under Huan Yi, and again at Fanwu in 232 BC.

Qin's commander Wang Jian realised the army could not take Zhao while Li Mu lived. The state instead bribed the king's favourite courtier, Guo Kai, to spread the rumour that Li Mu and his deputy Sima Shang were plotting rebellion. King Qian of Zhao — whom Sima Qian records as a man of no character who believed slander — sent replacements to arrest the general. Li Mu refused to hand over command, knowing what the replacement would mean; the king had him seized in secret and executed.

Three months later Wang Jian attacked. The replacement generals, Zhao Cong and the Qi mercenary Yan Ju, were routed; Yan Ju fled and King Qian was captured outside Handan. The state that had been Qin's last military equal fell in a single campaign season. Sima Qian's verdict, in four characters at the end of the chapter: 'Lian Po and Li Mu were not used; King Qian became a prisoner.'