During the late Eastern Han Dynasty, warlords rose across the land, locked in endless conflict.
During a campaign, Cao Cao laid siege to Xu Province. The governor, Tao Qian, sent an urgent plea to Liu Bei, requesting military assistance to break the encirclement.
Liu Bei immediately led his top generals Guan Yu, Zhang Fei, and Zhao Yun into the thick of battle, breaking through the siege to enter Xuzhou and assist Tao Qian in defending the city.
Tao Qian, seeing himself as old and incapable of protecting Xuzhou, and recognizing Liu Bei as a member of the Han imperial family with strong troops, intended to yield Xuzhou to him. Liu Bei declined, saying, "My merits are slight and my virtue thin; I came only out of righteousness to offer aid—how dare I harbor any improper ambition?"
The two pushed back and forth without reaching a conclusion. Their subordinates advised, "The enemy is at the city gates; let us first discuss how to repel them. Matters of yielding can be settled later." Liu Bei agreed, saying, "I will first write a letter to Cao Cao, urging him to withdraw. If he refuses, then we will engage him in battle."
Liu Bei immediately wrote a letter and dispatched a messenger to deliver it to Cao Cao. Upon opening it, Cao Cao read: "The realm is beset with endless troubles; you are a pivotal figure who must prioritize state affairs and refrain from pointless campaigns. I urge you to lift the siege on Xuzhou—for the sake of the empire and its people."
After reading the letter, Cao Cao flew into a rage and said, "Who does Liu Bei think he is? How dare he lecture me. I'll order an attack on the city immediately and see what Liu Bei is capable of."
Advisor Guo Jia saw this and advised, "Liu Bei has traveled from afar. You should first treat him with courtesy, and if that fails, then use force. My lord, first soothe Liu Bei with kind words, then advance to attack the city, and Xuzhou will fall quickly."
Cao Cao heeded Guo Jia's advice. Just then, news arrived that Lü Bu had breached Yanzhou and was preparing to attack Yang, startling Cao Cao, who planned to immediately withdraw his troops to rescue Yang. Guo Jia said, "We should take this opportunity to do a favor for Liu Bei, telling him that out of respect for him, we are lifting the siege of Xuzhou."
Cao Cao then wrote back to Liu Bei, announcing his withdrawal, and led his army away.
Later, the idiom "courtesy before force" came to describe first treating someone politely, and resorting to force only if that fails.
Source: *Romance of the Three Kingdoms*
Meaning of the Idiom: Later, the Chinese idiom "先礼后兵" came to describe first treating someone politely, and resorting to force only if that fails.