When King Kang's father King Gong died in 560 BC, Chu's enemy Wu seized the opportunity to invade Chu. Chief military commander Zigeng and general Yang Youji led the Chu army to repel the invaders. After the initial fight Zigeng feigned defeat. The Wu army chased the retreating Chu army to Yongpu, where they fell into an ambush and were soundly defeated. Prince Dang, the commander of the Wu army, was captured.
Battle of Zhanban
In 557 BC, just three years after the Battle of Yongpu, Chu fought the last major battle with its traditional enemy Jin at Zhanban. Chu was defeated and lost all of its territory north of Fangcheng, the Great Wall of Chu. The Battle of Zhanban marked the end of the eight-decade-long Jin-Chu rivalry, as a weakened Chu would be consumed by numerous wars with its new enemy Wu, culminating in the 506 BCBattle of Boju, when the Wu army would capture and destroy the Chu capital Ying. Meanwhile, Jin was increasingly riven by internal strife that would ultimately lead to its partition into the new states of Han, Zhao, and Wei.
In 549 BCDuke Ping of Jin attacked the Chu ally Qi. To help Qi, Chu attacked the Jin ally Zheng. King Zhufan of Wu seized the opportunity and induced the Chu vassal state Shujiu to switch its allegiance to Wu. The next year, Chu prime minister Qu Jian and general Zijiang led an army to punish Shujiu, again ambushing and routing the Wu army. Chu then annexed Shujiu.
Battle of Chaocheng
In 548 BC, soon after Wu's defeat at Shujiu, King Zhufan personally led an army to again invade Chu, attacking the Chu city Chaocheng. Greatly outnumbered by the Wu army, Chu general Niu Chen pretended to give up Chaocheng and left the city gate wide open. When the unsuspecting Zhufan entered the city, Niu Chen shot and killed him with an arrow. The Wu army fell into chaos and was again defeated. Zhufan's brother Yuji succeeded him as king of Wu.
Succession
King Kang was the eldest of King Gong's five sons, four of whom would ascend the throne. When King Kang died in 545 BC after 15 years of reign he was succeeded by his son Xiong Yuan and King Kang's younger brother Prince Wei served as the prime minister. Four years later, Prince Wei murdered Jia'ao and his two sons when he was ill, and usurped the throne. Prince Wei was later given the pejorative posthumous titleKing Ling of Chu. In 529 BC when King Ling was on an expedition against the State of Xu, his three younger brothers staged a coup d'etat and killed his son Crown Prince Lu. Xiong Bi, the third brother, ascended the throne, and the fourth brother Prince Zixi became the prime minister. When news of the coup reached King Ling's troops they abandoned him en masse, and in desperation King Ling killed himself. However, Xiong Qiji, the fifth brother, concealed the truth about King Ling's death from Zi'ao and Zixi. Instead, he pretended to be defeated by King Ling and said the king would soon return to the capital. Zi'ao and Zixi were so fearful that they both committed suicide; Zi'ao had been king for less than twenty days. Prince Qiji then ascended the throne and would come to be known as King Ping of Chu.