He ruled from 496 BC to 465 BC. In 496 BC, He Lv, the king of Wu, was defeated by the Vietnamese army. He Lu was injured and died, and his son Fu Cha was determined to take revenge. Gou Jian took the initiative to attack Wu the following year. In Fujiaoshan (now southwest of Wuxian County, Jiangsu Province), there was a fierce battle with Wu Bing, and the Vietnamese army was defeated. In order to save his strength, Gou Jian retreated to Huiji Mountain (now south of Shaoxing, Zhejiang) and used his tactics to make peace with Wu. After Gou Jian returned to China, he tasted all his courage and never forgot the shame of martial arts. He appointed Fan Li, Wen Zhong and others to reform the internal affairs and recuperate. Later, Gou Jian took advantage of Fu Cha's hegemony in the north and the emptiness of the country, invaded Wu, and killed the king in one fell swoop. Focha had to make peace after returning to China. Gou Jian constantly mobilized troops to attack Wu. In the twenty-fourth year of Gou Jian, Wu was besieged for three years, the city was broken, and Fu Cha committed suicide. Wu Wu died. Subsequently, Gou Jian sailed northward, and Song, Zheng, Lu and Wei joined the army in succession, and moved the capital to Langya (now Jiaonan, Shandong Province), where he joined forces with the governors of the Qi and Jin Dynasties and was officially recognized as the overlord by Zhou Yuanwang.
Gou Jian, the King of Yue, should actually have written "Sentence Jian". In ancient times, there was no word "hook", but the word "sentence" was used to communicate. The Historical Records published by Ganlong in Wuying Temple misquoted the improper supervision edition of Ming Dynasty and wrote it as "Gou Jian", which caused many mistakes in later generations and led to the accumulation of mistakes in modern times. For example, Chapter 11 of the Family of Goujian, the King of Yue in Historical Records wrote: "Goujian, the King of Yue, is a descendant of Yu, and the son of Shao Kang, the Xia emperor ..." We know that the modern Chinese character "sentence" and "hook" are separated, but some ancient names and places can't be changed at will when writing. The names of people are all "in dialogue" (speaking), but now Goujian.