Haijin

China's foreign trade was limited to irregular and expensive tribute missions, and the military pressure from the Mongols after the disastrous Battle of Tumu led to the scrapping of Zheng He's fleets.

[3] Existing revolts over the government salt monopoly and severe floods along the Yellow River provoked the Red Turban Rebellion.

King Gongmin of Korea had begun freeing himself from the Mongols as well, retaking his country's northern provinces, when a Red Turban invasion devastated the areas and laid waste to Pyongyang.

In Japan, Emperor Daigo II's Kenmu Restoration succeeded in overthrowing the Kamakura shogunate but ultimately simply replaced them with the weaker Ashikaga.

The loose control over Japan's periphery led to pirates setting up bases on the realm's outlying islands,[4] particularly Tsushima, Iki, and the Gotōs.

[11] Although the policy is now associated with imperial China generally, it was then at odds with Chinese tradition, which had pursued foreign trade as a source of revenue and become particularly important under the Tang, Song, and Yuan.

The large scale of private overseas trade had caused price competition for the Ming government's purchases, such as warhorses for the northern frontier, and funds had to be reallocated.

[14] A 1613 edict prohibited maritime trade between the lands north and south of the Yangtze River, attempting to put a stop to captains claiming to be heading to Jiangsu and then diverting to Japan.

[17] The usage of trade was also a powerful tool to entice foreign governments to abide by the tributary system and pressure uncooperative leaders.

[18] Parallels with Song and Yuan measures restricting outflows of bullion have led some to argue that it was intended to support the Hongwu Emperor's printing of fiat currency,[7] whose use was continued by his successors as late as 1450.

[21] Nonetheless, it may have been the case that the Hongwu Emperor prioritized protecting his state against the Northern Yuan remnants, leaving the policy and its local enforcers as the most he could accomplish[22] and his mention of them in his Ancestral Injunctions[11] as responsible for their continuation.

The policy offered too little—decennial tribute missions comprising only two ships—as a reward for good behavior and enticement for Japanese authorities to root out their smugglers and pirates.

[16] The Hongwu Emperor's message to the Japanese that his army would "capture and exterminate your bandits, head straight for your country, and put your king in bonds"[23] received the Ashikaga shogun's reply that "your great empire may be able to invade Japan but our small state is not short of a strategy to defend ourselves".

[16] Although the sea ban left the Ming army free to extirpate the remaining Yuan loyalists and secure China's borders, it tied up local resources.

[26] The initial wave of Japanese pirates had been independently dealt with by Chŏng Mong-ju and Imagawa Sadayo, who returned their booty and slaves to Korea;[5][6] Ashikaga Yoshimitsu delivered 20 more to China in 1405, which boiled them alive in a cauldron in Ningbo.

[33] Piracy dropped to negligible levels only after the general abolition of the policy in 1567[34] upon the ascension of the Longqing Emperor and at the urging of the governor of Fujian Tu Zemin.

[32] Maritime trade intendancies were reëstablished at Guangzhou and Ningbo in 1599, and Chinese merchants turned Yuegang (modern Haicheng, Fujian) into a thriving port.

[25][32] The end of the sea ban did not mark an imperial change of heart, however, so much as a recognition that the weakness of the later Ming state made it impossible to continue the prohibition.

[15] The lifting of the sea ban coincided with the arrival of the first Spanish galleons from the Americas, creating a global trade link that would not be interrupted until the following century.

[48] The galleon trade was supplied by merchants largely from port areas of Fujian who traveled to Manila to sell the Spaniards spices, porcelain, ivory, lacquerware, processed silk cloth and other valuable commodities.

The Qing regent Prince Rui resumed the sea ban in 1647, but it was not effective until a more severe order followed in 1661[36] upon the ascension of the Kangxi Emperor.

In an evacuation as the "Great Clearance" or "Frontier Shift", coastal residents of Guangdong, Fujian, Zhejiang, Jiangsu, and parts of Shandong were required to destroy their property[36] and move inland 30–50 li (about 16–26 km or 10–16 mi), with Qing soldiers erecting boundary markers and enforcing the death penalty on those beyond it.

[51] Repressive Qing policies such as the queue caused Chinese traders to emigrate in such large numbers, however, that the Kangxi Emperor began to fear the military implications.

The conflicts between the former residents and the newcomers such as the Hakka provoked lingering feuds that erupted into full-scale war in the 1850s and 1860s and that fueled Guangdong's piracy into the 20th century.

[60] By restricting imports mostly to bullion, however, it created strong pressure on the British—for whom tea had become the national drink over the course of the 17th century—to find any means possible to adjust the balance of trade.

A map of wokou raiding, 14th–16th centuries. The early pirates were mostly based on outlying Japanese islands but targeted the Japanese as well as Korea and Ming China. The later ones were mostly Chinese dispossessed by Ming policy.
Territory held (red) or influenced (pink) by Koxinga and his Ming partisans / pirates