Case of Lord Mengchang Imprisoned in Qin

During the Warring States period, Lord Mengchang (Tian Wen) of Qi was invited to serve as chancellor in the State of Qin. Shortly after his arrival, King Zhaoxiang of Qin, persuaded by slander that Mengchang's loyalty remained with Qi, detained him and planned his execution. Seeking release, Mengchang appealed to the king's favored concubine, who demanded the rare white fox-fur coat already gifted to the king. A retainer skilled in burglary entered the palace treasury, retrieved the coat, and presented it to her. The concubine then convinced the king to free Mengchang. Fearing revocation of the order, Mengchang and his followers fled immediately under forged identities. At Hangu Pass, the gates were shut until dawn's first cockcrow; a retainer mimicked a rooster, triggering early crowing from nearby birds and allowing them to pass. The king's pursuing troops arrived too late, and Mengchang returned safely to Qi. The episode stands as a historic instance of arbitrary imprisonment resolved not by trial but by cunning escape.

No formal trial was held. King Zhaoxiang initially ordered Mengchang's release under the concubine's influence but quickly rescinded the decision and sent soldiers to capture him. Mengchang successfully escaped Qin territory and returned to Qi, facing no further legal proceedings. The de facto outcome was a failed extrajudicial detention and an unpunished escape.

Whether King Zhaoxiang's imprisonment of Lord Mengchang constituted lawful sovereign action or arbitrary political persecution; whether the retainers' theft of the coat and the deceptive opening of the pass gate amounted to criminal acts; and whether the detention violated any recognized inter-state immunity for a visiting chancellor.

The case gave rise to the enduring idiom "cockcrow and dog-thievery" (鸡鸣狗盗), emphasizing that even humble skills can prove invaluable. It highlighted the precarious nature of cross-state political service during the Warring States era and cemented Lord Mengchang's legacy as a patron who attracted diverse, resourceful retainers. The affair also illustrated the vulnerability of foreign dignitaries to abrupt sovereign caprice in ancient China.