Shi Xianggu (1775-1844) was a prostitute from Guangdong (Canton) province who started her pirate career in 1801 when she married Zheng Yi, leader of the Red Flag pirate fleet. After her marriage, Shi became known as Zheng Yi Sao (literally "wife of older brother Zheng Yi").¹ The couple went to Annam (present day Vietnam) to fight in the Tay Son rebellion.² After returning to Guangdong, China, they conducted joint operations with another pirate Wu Shi'er, rapidly extending their scope of influence and eventually establishing the Cantonese Pirate Coalition. Prior to forming the coalition, the Zhengs already had 200 ships under their command. The size of their fleet expanded to 600 ships after the coalition was established.³

After Zheng Yi died in 1807, Xianggu shared leadership of the fleet with Zheng Yi's deputy Zhang Bao. Zhang Bao, also known as Zhang Baozai ("Zhang Bao the Kid"), was then only 21.⁴ He was a fisherman's son. The Zhengs kidnapped Zhang when he was 15. He proved himself a brave fighter and intelligent leader and was soon adopted by the Zhengs as their foster son.⁵ Zhang was believed to have been Zheng Yi's boy favorite as well as Shi Xianggu's lover and later husband. Contemporary records held that Zheng Yi Sao was officially the commander and Zhang Bao, being her subordinate, had to seek her approval for administering any rewards and punishments to the crew.⁶

Xianggu and Zhang Baozai took the Red Flag Fleet to unprecedented levels of power and organization.⁷ By 1809, there were 70,000 pirates under their command. The level of armament of Zheng Yi Sao's pirate fleet was thrice that of the English fleet and Spanish armada combined at the 1588 battle between England and Spain.⁸ Shi Xianggu was effectively mistress of the high seas, repeatedly defeating the navy sent to capture the pirates. Both the civil and military arms of the Guangdong government were powerless against her.⁹ Shi Xianggu is said to far surpass her two husbands in fame, bravery, strategy and spirit. Her life has been immortalized in the novel Zheng Yi Sao by Yang Wanxiang.¹⁰