Zheng Yi Sao led a large group of pirates that pillaged the South China Sea at the beginning of the 19th century. Zheng Yi, her husband, founded the confederation before he died in 1807. After that, Zheng Yi Sao took control of the confederation, increased the pirate fleet, and defeated three flotillas of the Chinese Imperial Navy. She ended the confederation when she decided to accept the pardon offered by the Chinese government, and the Chinese, British, and Portuguese navies were unable to bring her to justice. This woman terrorized the South China coast, where she robbed, killed, and sold thousands of people into slavery.

Zheng Yi Sao was a prostitute in Canton before getting married to Zheng Yi in 1801 at the age of 26. According to different accounts of the couple, Zheng Yi sought out Zheng Yi Sao due to her reputation as an intelligent businesswoman. She would utilize the secrets she found out as a prostitute to hold control over her well-off and strong clients. She was also said to be good with money, which would help her later in her career as a pirate. Chinese women were frequently captains, mariners, and pirates. It was also abundantly clear that her adversaries' commanders regarded her as extremely competent. The talk at the time was that after Zheng Yi and Zheng Yi Sao's marriage Zheng Yi Sao requested equivalent control of armada. There was only one other record female commander in the history of pirate leadership.

Chang Pao was Zheng Yi protege and his lover. This type of relationship wasn’t unusual between junior and senior Chinese privateers. Chang Pao was poised to inherit the Red Flag Fleet after Zheng Yi's death, but this didn’t exactly transpire. Instead, Zheng Yi Sao took him as a lover and, after solidifying their bond, pulled herself back into power. Cheng Pao became the second in command instead of the head of the fleet.

Zheng Yi continued to expand his fleet during his lifetime. Zheng Yi Sao continued her husband's efforts and expanded the fleet to about 800 large ships in 1807. Many of these ships were junks, a traditional Chinese sailing vessel. The ships could carry about 800 tons of cargo and about 40 cannons. Junks had no keel and a retractable rudder. This means that the ship can go into shallow water to launch a surprise attack on anchored ships. Junks also carried other smaller boats which carried 20 men and several swivel cannons. Those smaller vessels were used to approach enemy or targeted ships undetected. These smaller ships were used to approach or target enemy ships unnoticed. Zheng Yi Sao's confederation had over 70,000 men. Similarly, Blackbeard commanded four ships and 300 pirates.

The sailors who surrendered without a fight were not tortured or injured; instead, they watched as their cargo was stolen. Sailors who resisted the pirates were tortured or executed if captured. European sailors were treated a little better because they could be ransomed, but because it wasn't a quick process, they were forced to live in horrible and cramped conditions for months. Many of these raiding tendencies were also seen in the Caribbean.

Captured Chinese were forced to either join the pirates or were flogged to death, while the captured Europeans were forced to assist in the attacks on the village. During these raids, pirates collected the heads of their victims and tied them in pairs around their necks as trophies.

In two separate confrontations, July 1808 and July 1809, obliterated the Chiese Navy fleets guarding the area between Portuguese Macao and Canton. The battle in July 1808 lasted 16 hours. The pirates won and after the battle, the Chinese admiral committed suicide from the humiliation. The battle in July 1809 needed imagination as there was no wind to move either of the fleets. So, Zheng Yi Sao ordered her pirates to swim and board the Chinese ships. They followed her orders and did just that. The coastal towns were then torched, as happened in Sansham in August. In this village, 80 villagers were beheaded and their heads were hung on trees by the water as a warning to others. Then on September 1, hundreds of innocent villagers were killed during a campaign on the island of Tao-chiao. The total from this terror campaign which landed the pirates 25 kilometres from Canton was 10,000. During the campaigns of 1808 and 1809, pirates also attacked strong and well-armed European ships, such as the two Portuguese ships guarding Macao in 1809.

As the problem of piracy became more serious, the Chinese authorities have stepped up their efforts to solve it. Not only was the Chinese authority's new mission becoming a problem for Zheng Yi Sao, but it was becoming increasingly more difficult for her to keep the pirate confederation together. Kuo P’o-Tai, the leader of the Black Flag Fleet, became extremely jealous of Chang Pao’s elevated role and possibly even the affection Zheng Yi Sao directed toward Chang Pao. Kuo P’o Tai refused to help the Red Flag Fleet in the battle against the Chinese and Portuguese fleets in November 1809. In December Chang Pao attacked Kuo P’o Tai due to his disloyalty. Kuo P’o Tai won the battle, but realizing that his time with the confederation had ended, surrendered to authorities in January 1810. He got a pardon and was employed as a pirate-hunter. With a large portion of her fleet gone or destroyed Zheng Yi Sao surrendered in 1810. 

But even with her destruction, Zheng Yi Sao decided to go out in style. She sailed her remaining fleet of 260 junks with all their flag flying into the Canton harbour. Zheng Yi Sao marched straight up to authorities and demanded a pardon on April 18, 1810. She even gained favourable terms allowing her and her pirates to keep their plunder as long as they surrendered their weapons and ships. The collapse of the confederation did not end piracy in China but did mark the last major wave of piracy.