In 506 BC, King Helü of Wu defeated Chu in the Battle of Boju and captured the Chu capital Ying (present day Jingzhou). Helü's advisor Wu Zixu, who was previously forced into exile by the already deceased King Ping of Chu and craved vengeance for the brutal execution of his father and brother, exhumed the King Ping's corpse and lashed it posthumously. This was a great humiliation for the Chu state, so Shen Baoxu, a Chu official and a former friend of Wu Zixu, travelled to the Qin court and pleaded for assistance from Duke Ai of Qin to recover the capital. After Duke Ai initially refused to help, Shen spent seven days crying in the palace courtyard, and Duke Ai was eventually moved by his devotion and agreed to send troops to assist Chu. The famous poem named "No Clothes" (), recorded in the "Classic of Poetry", was a battle hymn personally composed by Duke Ai to boost the morale of the Qin troops. In 505 BC, the Qin and Chu armies jointly defeated Wu in several battles, allowing King Zhao of Chu to be restored and return to the recaptured capital.