因祸得福 — “A blessing in disguise”

Guan Zhong, also known as Yi Wu, was from Yingshang. In his early years, he was poor and engaged in trade in Nanyang. He was good friends with Bao Shuya. After failing to assist Prince Jiu, he was recommended to Duke Huan of Qi by Bao Shuya. Duke Huan of Qi appointed Guan Zhong as his Prime Minister. Guan Zhong was skilled at turning unfavorable situations around, changing passive roles into active ones, and ultimately achieving success.

One day, Duke Huan of Qi was boating on a lake with his wife, Lady Cai. Lady Cai was familiar with water, often enjoyed boating, and moved as freely in a boat as in a carriage. However, Duke Huan was not good with water and rarely boated. On a whim, Lady Cai played a prank on him, shaking the boat vigorously. As the boat swayed back and forth, Duke Huan's face turned pale with fright, and he shouted, "Stop shaking it!" Lady Cai ignored him and laughed heartily. Duke Huan was furious. After landing, he sent Lady Cai back to her home state of Cai.

Duke Huan did this merely out of temporary anger, without intending to divorce her. But the State of Cai took it seriously and quickly remarried Lady Cai. Duke Huan was enraged and wanted to immediately lead troops to attack Cai. However, for a powerful overlord to wage war on his wife's home state merely because of a wife's prank was highly undignified. So, Guan Zhong suggested, "We can first march towards Chu and question why they have not paid tribute to the Son of Heaven (the Zhou King) on time. As Cai has always been close to Chu, attacking Cai would then become justifiable." Thus, the Qi army marched south to the Chu border.

To further expand Qi's influence, Guan Zhong also advised Duke Huan to launch a campaign against Lu, which resulted in a great victory, occupying Suiyi (now northwest Ningyang, Shandong) in Lu. During the signing of a treaty between the Duke of Lu and Duke Huan of Qi, Lu general Cao Mo seized Duke Huan and threatened him to return the occupied territories. Duke Huan had no choice but to sign a treaty agreeing to return the lands taken during the war. Afterward, Duke Huan felt humiliated and wanted to kill Cao Mo. Guan Zhong immediately dissuaded him, saying, "You must not kill him. A few cities in Lu are merely a small gain; establishing prestige among the feudal lords is the great gain. If the various feudal lords know that you would not even break an alliance made under duress, then you will establish great credibility throughout the land!" Indeed, after this incident, all the feudal states regarded Duke Huan of Qi as a man who kept his word and were willing to honor him as their overlord. Soon, Duke Huan became the hegemon among the various feudal states, one of the Five Hegemons of the Spring and Autumn Period.