After Emperor Gaozu of Han, Liu Bang, passed away, Empress Lü seized power. She enfeoffed members of the Lü clan as princes and marquises while suppressing ministers who held dissenting views.
In 180 BCE, after Empress Dowager Lü's death, her will appointed her nephew Lü Chan as Chancellor and Lü Lu as commander of the imperial guard in the capital, setting the stage for the Lü clan to seize the Han throne from the Liu family.
The founding heroes under Liu Bang were furious at the Lü clan's conspiracy. Grand Commandant Zhou Bo and Chancellor Chen Ping were determined to restore power to the Liu family, but military authority remained in Lü hands, leaving them powerless to act.
After deliberation, they decided that since Lu Lu was closest to Quzhou Marquis Li Shang and his son, they placed Li Shang under house arrest and coerced his son Li Ji into tricking Lu Lu into surrendering his military command. With his father held hostage, Li Ji had no choice but to follow the plan, telling Lu Lu, "The princes and ministers have no objection to your being made a king. But as long as you hold the army, they suspect you of plotting rebellion. Why not hand over the troops to the Grand Commandant and return to your fiefdom to enjoy life? That way, you can avoid a united front of ministers rising against you."
Lü Lu, never one for grand ambitions, found his friend's advice reasonable and went to consult other members of the Lü clan. Their conflicting opinions left him so flustered that he dragged his friend Li Ji off for a hunt. On their way back, they passed the mansion of Lü Xu, Lü Lu's aunt and the Marquess of Linguang, so he stopped in to visit. When Lü Xu heard that her nephew intended to surrender military command, she flew into a rage, hurling the family's jewels to the floor and scolding him, "Once we lose control of the army, our entire Lü clan will have no place to bury our dead! What use are these trinkets then?"
Li Ji reported Lu Xu's words to Zhou Bo and Chen Ping. Just then, Cao Zhu, son of former Chancellor Cao Shen, arrived with news: General Guan Ying and Prince Liu Xiang of Qi had allied their forces, preparing to return to the capital to eliminate the Lü clan. Chen Ping and Zhou Bo's spirits lifted, and they decided to act immediately, coordinating from within and without.
With the help of Ji Tong, son of Liu Bang's loyal minister Ji Xin, Zhou Bo used the imperial tally Ji Tong provided to enter the command tent of the Northern Army, the elite guard of the capital. Fearing that Lü Lu might resist, Zhou Bo sent Li Ji and the imperial steward Liu Jie to coax Lü Lu, saying, "The Grand Commandant has been ordered to take command of the Northern Army. You'd best hand over your seal of command, or disaster will befall you, and you'll regret it too late!"
Lü Lu had been wavering over whether to surrender his military command
After seizing command of the military, Zhou Bo acted swiftly, executing the entire Lü clan and installing Liu Heng, the Prince of Dai, as emperor—known to history as Emperor Wen of Han.
Li Ji played a key role in the campaign to eliminate the Lü clan, earning him the title of Marquis of Quzhou, inherited from his father. However, some accused him of betraying a friend for personal gain, tarnishing his reputation as a man who would sacrifice loyalty for profit.
Later, people used the idiom "Jian Li Wang Yi" to describe someone who forgets justice and loyalty when seeing personal gain.
Source: *Book of Han*, "Biographies of Fan, Li, Teng, Guan, Fu, Jin, and Zhou"
Meaning of the Idiom: Later, the Chinese idiom "见利忘义" came to describe how someone forgets justice and loyalty when seeing personal gain.