Emperor Wu of Han's fifth son, Prince Liu Xu of Guangling, was rough and unrestrained, caring only for feasting and amusement, which greatly displeased his father.
After Emperor Wu died, the throne passed to his eight-year-old son Liu Fuling, known historically as Emperor Zhao of Han, with General Huo Guang and others serving as regents.
When Liu Xu saw that he was passed over for the throne, he grew deeply resentful and hired a sorceress to curse Emperor Zhao to an early death. As luck would have it, the young emperor died at just twenty-one. Filled with renewed hope, Liu Xu expected General Huo Guang to crown him emperor next.
However, Huo Guang and his supporters bypassed him and installed Emperor Wu's eldest grandson, Liu He, the Prince of Changyi, as emperor, infuriating Liu Xu. But Liu He lasted only 27 days on the throne; Huo Guang and his allies, seeing he was unfit to rule, deposed him and instead installed Emperor Wu's great-grandson, Liu Xun, as Emperor Xuan of Han.
When Liu Xu learned of this, he flew into a rage, declaring, "I am Emperor Wu's own son, yet Emperor Xuan is merely his great-grandson—this is utterly unjust!" So he secretly conspired with King Liu Yanshou of Chu, plotting to raise an army in rebellion.
However, the plot was not kept secret and was exposed. Emperor Xuan, considering Liu Xu was his own grand-uncle, pardoned his crime and only executed Liu Yanshou.
After receiving a pardon, Liu Xu briefly restrained himself, but soon his son Liu Bao was executed for crimes, and Liu Xu himself was held accountable for indulging his wayward son. Emperor Xuan issued an edict stripping Liu Xu of his noble title. Nursing a deep grudge, Liu Xu once again employed a female shaman to curse the emperor, praying for his early death.
However, the curse plot was exposed. Emperor Xuan sent officials to investigate and discovered that Liu Xu, aside from trusting the witch, had surrounded himself almost entirely with dishonest men. Knowing he could not escape death, Liu Xu hanged himself.
Historian Chu Shaosun, writing biographies for three princes including Liu Xu, remarked with emotion: "When mugwort grows among hemp, it stands straight without support." This means a person living among good people becomes good; if they befriend bad people, they become bad. Liu Xu had no good people around him, so he turned bad, ultimately meeting a tragic end.
Later, the idiom "Peng Sheng Ma Zhong" (vines growing among hemp) came to describe the influence of environment on a person.
Source: *Records of the Grand Historian*, "Hereditary Houses of the Three Kings"
Meaning of the Idiom: Later, the Chinese idiom "蓬生麻中" came to describe the influence of environment on a person.