During the Spring and Autumn period, the states of Jin and Chu were constantly at war. In 584 BC, King Gong of Chu launched an attack on Zheng, prompting Duke Jing of Jin to rally Qi, Lu, Song, and Wei to rescue Zheng. The armies clashed in Zheng territory, and Chu suffered a crushing defeat. A Chu official named Zhong Yi was captured and taken as a prisoner of war by Jin forces.
After the Jin army returned home, they imprisoned Zhong Yi in a military arsenal. Though captive, Zhong Yi never forgot his Chu identity—each day he wore his Chu cap, stood facing south, and gazed into the distance, longing for his homeland and kin.
Two years passed in a flash. One day, Duke Jing of Jin came to inspect the armory, where he saw Zhong Yi and asked in great surprise, "Why is a prisoner locked up in the armory, wearing a Chu-style hat? Who is he?"
The official in charge of the armory replied, "He is a prisoner from the state of Chu captured two years ago, named Zhong Yi." Duke Jing of Jin, upon hearing this, sent someone to remove Zhong Yi's shackles, called him before him, offered a few words of comfort, and then asked, "What did your family do in the state of Chu?" Zhong Yi answered, "My ancestors were music officials." Duke Jing, now intrigued, pressed further, "Can you play music?" Zhong Yi replied, "It is my family's hereditary profession—how could I not?"
After hearing this, Duke Jing of Jin ordered a zither brought forth and asked Zhong Yi to play. Zhong Yi straightened his robes, sat upright before the instrument, and began to perform. The melody he played was a Chu tune, rich with the flavor of the southern state, fully expressing his longing for his homeland.
After hearing this, Duke Jing of Jin asked, "What kind of person is your King of Chu?" Zhong Yi replied, "That is not something I should know."
Duke Jing of Jin pressed him repeatedly, and Zhong Yi finally said, "I only know that when the King of Chu was crown prince, he deeply respected Lingyin Gongzi Yingqi and Sima Gongzi. I truly know nothing else—please forgive me, Your Majesty!"
Duke Jing of Jin nodded and left the armory to return to his palace. Some days later, he told this matter to his senior minister Fan Wenzi. After hearing it, Wenzi said, "Your Majesty, based on Zhong Yi's words and deeds, he is an honest gentleman. It would be better for you to release him and let him return to the State of Chu, to promote peace between Jin and Chu and end the years of continuous war between our two states."
Duke Jing of Jin, following the advice of his minister Fan Wenzi, ordered the release of Zhong Yi back to Chu. Upon returning to Chu, Zhong Yi indeed played a crucial role in reconciling the states of Jin and Chu.
Later, the idiom "Southern Cap, Chu Prisoner" came to describe someone imprisoned in a foreign land, yet maintaining noble integrity and longing for their homeland, and was also used to refer to a prisoner.
Source: *Zuo Zhuan*, "Duke Cheng's Ninth Year"
Meaning of the Idiom: Later, the Chinese idiom "南冠楚囚" came to describe how someone imprisoned in a foreign land yet maintains noble integrity and longs for their homeland and also refers to a prisoner.