The Murder of Duke Xiang of Qi and the Usurpation by Gongsun Wuzhi

In the winter of 686 BC, Duke Xiang of Qi dispatched officers Lian Cheng and Guan Zhifu to garrison Kuiqiu, promising to relieve them when melons ripened. A year passed with no replacement, and when they requested relief, the Duke publicly humiliated them. Enraged, they conspired with Gongsun Wuzhi, the Duke's disgruntled cousin whose privileges had been revoked. Lian Cheng also enlisted his cousin, a neglected concubine, as a spy. Learning the Duke was hunting at Beiqiu, they ambushed and murdered him. Gongsun Wuzhi was then installed as the new ruler of Qi. The usurpation plunged the state into turmoil; Wuzhi was assassinated soon after by minister Yong Lin, triggering a succession crisis that eventually brought Duke Huan to power.

No formal judicial trial took place. The usurper Gongsun Wuzhi was killed by minister Yong Lin shortly after his ascension. Lian Cheng and Guan Zhifu were likely eliminated in the ensuing chaos. Subsequent succession struggles recognized Duke Huan as the legitimate heir, effectively nullifying the usurpation through political settlement rather than legal adjudication.

The moral justification for regicide stemming from the Duke's broken promise and public disgrace; the legitimacy of Gongsun Wuzhi's claim to the throne based on ancestral favoritism and personal grievance; the tension between personal vengeance and political loyalty under the feudal order.

The assassination triggered a prolonged succession crisis between Prince Jiu and Prince Xiaobai, ultimately leading to the reign of Duke Huan of Qi. With Guan Zhong as chancellor, Qi enacted sweeping reforms and became the first hegemon of the Spring and Autumn period, shaping the "Honor the King and Expel the Barbarians" policy and profoundly altering the political landscape of ancient China.