During the struggle among the major feudal states for hegemony, large states annexed smaller ones and expanded their territories. However, the rulers of these powerful states had to grant newly acquired lands to their meritorious ministers. As a result, the ministers' power grew significantly. Conflicts frequently arose among these ministers, intensifying domestic tensions within the major states. All desired a temporary halt to the wars of hegemonic contention.
For this reason, Xiang Shu (pronounced "shù"), a minister of the State of Song, traveled tirelessly between the states of Jin and Chu, acting as a mediator.
In 546 BC, Jin, Chu, and several other states held the "Conference of Disarmament" (Mi Bing Hui Yi; "Mi" meaning "to stop") in the State of Song. At this conference, ministers from Jin and Chu represented the northern and southern alliances respectively, concluding a peace agreement and establishing a covenant. The agreement stipulated that, except for the two major powers of Qi and Qin, all smaller states must pay tribute equally to both Jin and Chu. Jin and Chu would share hegemony, and for over fifty years afterward, no major wars erupted.
After King Ping of Chu, the grandson of King Zhuang of Chu, ascended the throne, the State of Chu gradually declined. In 522 BC, King Ping of Chu decided to depose his original crown prince, Prince Jian. At that time, Prince Jian and his tutor, Wu She, were guarding the city of Chengfu (in present-day Xiangcheng County, Henan). Fearing Wu She's opposition, King Ping first summoned Wu She to the capital and falsely accused Prince Jian of plotting rebellion.
Wu She adamantly refused to admit the false charges and was immediately imprisoned.
King Ping simultaneously sent assassins to kill Prince Jian and forced Wu She to write a letter to his two sons, Wu Shang and Wu Zixu, summoning them back to the capital so they could all be eliminated together. The elder son, Wu Shang, returned to the capital Ying (northwest of present-day Jiangling, Hubei; "Ying" pronounced "yǐng"). He was executed alongside his father, Wu She, by King Ping of Chu. Prince Jian, having received advance warning, fled to the State of Song with his son, Prince Sheng.
Wu Zixu, Wu She's other son, also escaped from Chu. He reached Song and found Prince Jian. Unfortunately, civil unrest broke out in Song, so Wu Zixu fled with Prince Jian and Prince Sheng to the State of Zheng, hoping Zheng would help them take revenge. However, Duke Ding of Zheng refused their request.
Eager for vengeance, Prince Jian conspired with some Zheng ministers to seize Duke Ding's power and was executed by the Duke. Wu Zixu had no choice but to flee Zheng with Prince Sheng and seek refuge in the State of Wu (its capital in present-day Suzhou, Jiangsu).
King Ping of Chu had long issued a bounty for Wu Zixu's capture, commissioning portraits of him to be hung at city gates throughout Chu and instructing local officials to conduct strict inspections.
After escaping Zheng, Wu Zixu and Prince Sheng traveled by night and hid by day, eventually reaching the Zhaoguan Pass (north of present-day Hanshan County, Anhui), the border between Wu and Chu. The guards at the pass conducted extremely rigorous checks. Legend says Wu Zixu, overwhelmed with anxiety, couldn't sleep for several consecutive nights, and his hair turned completely white from worry. Fortunately, they encountered a kind-hearted man named Dong Gao Gong, who sympathized with Wu Zixu and took him into his home. Dong Gao Gong had a friend whose appearance resembled Wu Zixu somewhat. Dong arranged for this friend to impersonate Wu Zixu and pass through the checkpoint. The guards captured this decoy Wu Zixu, while the real Wu Zixu, his hair now fully white and his appearance altered, went unrecognized and slipped through the pass.
After passing Zhaoguan, fearing pursuit, Wu Zixu hurried forward. Ahead lay a great river blocking his path. As Wu Zixu grew desperate, an old fisherman rowed a small boat toward him and ferried him across the river.
Once across the river, Wu Zixu was deeply grateful. He removed the precious sword at his side and offered it to the old fisherman, saying, "This sword was bestowed upon my grandfather by the King of Chu and is worth a hundred catties of gold. I give it to you now, as a token of my heartfelt appreciation."
The old fisherman replied, "The King of Chu has offered a reward of fifty thousand dan of grain for your capture and promised the rank of a minister to anyone who reports you. If I don't covet such a reward or title, why would I want your sword?"
Wu Zixu quickly apologized to the old fisherman, retrieved his sword, and took his leave.
Wu Zixu arrived in Wu, where Prince Guang of Wu was plotting to seize the throne. With Wu Zixu's assistance, Prince Guang assassinated King Liao of Wu (pronounced "liáo") and proclaimed himself king—King Helü of Wu (pronounced "hé lǘ").
After King Helü ascended the throne, he appointed Wu Zixu as a minister to help administer state affairs and employed the general Sun Wu, a brilliant military strategist. Relying on Wu Zixu and Sun Wu, King Helü reorganized his military and first annexed several neighboring small states.
In 506 BC, King Helü appointed Sun Wu as commander-in-chief and Wu Zixu as deputy commander, personally leading a large army to attack Chu. They won victory after victory, utterly defeating the Chu forces and advancing all the way to the Chu capital, Ying.
By then, King Ping of Chu had already died, and his son, King Zhao of Chu, had fled. Wu Zixu harbored intense hatred toward King Ping. He dug up King Ping's tomb, exhumed his corpse, and whipped it fiercely.
The Wu army occupied the capital Ying. The Chu minister Shen Baoxu fled to the State of Qin to seek aid. Duke Ai of Qin initially refused to send troops. Shen Baoxu lingered outside the Qin palace gates, weeping day and night, for seven days and seven nights straight. Duke Ai of Qin was finally moved and declared, "Though Chu may be tyrannical and unjust, with such a loyal minister as this, how can we stand by and watch it perish?"
Duke Ai of Qin then dispatched troops to rescue Chu, defeated the Wu army, and forced King Helü of Wu to withdraw his forces and return home.
Upon returning to the Wu capital, King Helü attributed the primary credit for the victory to Sun Wu. Sun Wu, however, had no desire for an official post and retired to a life of seclusion in his hometown. The military treatise he left behind, *The Art of War*, is China's earliest outstanding work on military strategy.