In the early days of the Ming dynasty, Emperor Taizu Zhu Yuanzhang had imposed the harsh maritime ban—"not a single plank may go to sea"—a policy that had been debated for years. He did so to guard against Japanese pirates along the coast and the threats and harassment posed by the remnants of Zhang Shicheng, Fang Guozhen, and others, as well as to strengthen the central government's control over the provinces. Its purpose was to clean up maritime affairs and defend against the pirates.
But from the Jiajing and Longqing eras onward, the maritime ban had gradually changed in nature.
On the surface, the Ming court and its officials continued to uphold the ban and enforce strict inspections. They also kept implementing various policies to investigate, confiscate, and prevent smuggling. But in secret, smuggling and maritime trade in Fujian, Zhejiang, and Guangdong had instead grown increasingly prosperous.
It turned out that foreign countries overseas greatly prized Ming specialties such as silk, porcelain, tea, and cloth. The Ming also needed overseas wealth, such as silver from Japan and gold, spices, and other rare goods from the West. And since maritime trade could often bring profits ten times greater—or more—the result was only natural: certain people began conspiring with one another and taking risks.
However, because the maritime ban was in force, smuggling was not something just anyone could get involved in. Most of the maritime trade was actually controlled by powerful clans in Jiangnan and along the coast, such as local noble families, officers in the guard garrisons, and high-ranking officials and commandery princes based in Yingtian Prefecture.
Some colluded with maritime merchants in secret, using their authority to shield smugglers and take a cut of the profits. Others simply kept their own fleets, claiming they were meant to escort grain