Helv, with the personal name of Guang and the surname of Ji, was the King of the Wu State in the late Spring and Autumn Period. He was also known as Prince Guang before ascending the throne.

In 515 BC, Zhuan Zhu, a warrior, killed King Liao of Wu at a party under the order of Prince Guang, who therefore took the throne himself and was historically known as "King Helv of Wu".

After he became king, Helv launched revitalization plans to strengthen the country and to enrich the people. He recruited a lot of talents and put Wu Zixu, Sun Wu and other able persons in important positions. Meanwhile, he promoted a series of incentive policies and greatly developed agricultural production, gradually strengthening the political, economic and military power of the Wu State.

In 506 BC, King Helv launched an offensive against the State of Chu, inflicting a crushing defeat on the Chu army. The success was an unprecedented case of capturing the capital of a big state in the Spring and Autumn Period. In 505 BC, when the State of Wu was under attack of the State of Yue, King Helv personally led his troops to the battle, putting the Yue Army to rout. In 504 BC, King Helv launched another attack against the Chu State, forcing it to relocate its capital. From then on, the State of Wu enjoyed a great reputation.

In 496 BC, King Helv led his troops to attack the State of Yue. The two sides fought in what is now the south of Jiaxing in Zhejiang Province. In the end, the Wu army was defeated and King Helv died of injuries sustained in the battle. He was buried in Huqiu of Suzhou.