Japanese Pirates in the Late Medieval and Early Modern East Asia.

In the Japanese language `kaizoku` is the word for pirate but if you ask a Japanese what their image of kaizoku is, they will give an image of a European pirate, or Captain Jack Sparrow, hahaha. In Japan, Murakami pirates, who ruled the Japanese inland sea region in the 16th century are a different breed of pirate and I hope to write about them separately. So, what is `Wako`? In Chinese and Korean historical records, the word Wako is used which literally means `Japanese piracy`. This term refers to groups of ungoverned raiders that frequently attacked coastline areas along the Korean Peninsula to Southern China in the 14th to 16th centuries.

Wako, originally attacked trade ships along coastal routes between China, Korea and Japan however, over time they became more aggressive and began to plunder crops and abduct people in order to sell them as slaves in the inland areas of the Korean Peninsula. Two periods of violent plunder by the Wako are very evident, one being the latter half of the 14th century, when they mainly attacked the Korean Peninsula, and the other was the mid-16th century, when they attacked the coastal area of China. The term Wako has never been found in any Japanese document written at the time, while it frequently appeared in Chinese and Korean documents. Although Wako indicates Japanese piracy, the Wako groups are believed to have consisted of only 30% Japanese, most of the raiders were from China and Korea.

Wako can be described as pirates, smugglers or raiders. Most were peasants and fishermen who lived along the coastal areas and islands in East China Sea. We should consider that the Wako partially consisted of people living in the Korean Peninsula, China, Southeast Asia, or even those who emigrated from Mongol lands when the Yuan dynasty occupied the areas around East China Sea.  Some studies actually trace back early piracy and conclude that it was the result of the failed Mongol invasions.  There was a third invasion planned for 1283 which did not go ahead.  However, during preparations, working conditions under the Yuan was becoming increasingly terrible.  Dock workers, sailors, merchants and soldiers were simply used as slave labour, so thousands simply deserted and joined pirate groups.


According to research, Wako began to loot in the coastal area of Southwest Korea every year only after 1350.  As for their looting, sources report the following: (1) Rice and other grains: They pillaged the warehousing that held rice and other crops as items of tribute for the Korean authorities and attacked the vessels carrying tributes. (2) Residents: Coastal residents were kidnapped and/or held captive. They were not only brought to Japan but also sometimes sold to the Ryukyus as slaves. Goryeo officials frequently requested Japanese authorities to exterminate the Wako and to repatriate the abducted Goryeo people. Surely, the political situation in Japan was related to the cause of activating the Wako. After the Kamakura Shogunate was ruined in 1333, the Japanese administration in Kyoto split over two courts, the North Court in which the Muromachi Shogunate was established and the South Court. With this split, the civil war broke out in all of Japan. Particularly in Kyushu, the western island of the Japanese archipelago, the war between these two political powers came to such a stalemate that the poor inhabitants, especially those on the northwest coast of Kyushu where agricultural productivity was low, began to plunder.  In this region the Matsuura pirates began to to get a foothold and thereafter the people of various origins gradually turned to the Wako for their livelihoods. Besides the Korean Peninsula, the Wako also attacked coastal areas of China that were in turmoil owing to the transition from the Yuan dynasty to the Ming. The Ming dynasty, which was established in 1368, frequently requested the suppression of the Wako against Japan, but the political situation in Kyushu was still so unstable that the Japanese authorities were unable to suppress the movements of the Wako.


However, when the civil war in Japan came to an end in 1392, the suppression of the Wako in Kyushu by the new Muromachi Shogunate became effective. Meanwhile, the Goryeo dynasty perished in the Korean Peninsula in 1392 and the Joseon dynasty was established, they also engaged in active diplomacy with the Japanese Shogunate and the lords of Kyushu under the Shogunate, and strongly demanded the suppression of the Wako, although the Matsuura pirate kings were still relatively independently organised.  Moreover, the Joseon improved the defense force against piracy and adopted a policy to include the Wako on their side. Specifically, the Joseon authority permitted peaceful trade between Japan and Korea, and they set up residential areas for traders at the three ports in southeast Korea (Busan, Ulsan, and Naei (now Jinhae)). These policies were successful, and many members of the Wako surrendered to the Joseon and came to engage in trade with Japan, the Ryukyus, and Korea. Even in the Ming dynasty, as the civil war in the early 15th century converged and governance stabilized, coastal defenses were strengthened and the new Haijin policy was introduced to ban maritime activities like private trades and voyaging. In this manner, the Wako’s plundering in the East China Sea decreased gradually. Ethnic diversity of the Wako and many people joining the Wako pirate groups were residents engaged in fishery and shipboarding in Tsushima Island and in the coastal areas of northwest Kyushu (such as Matsuura and the Goto Islands in Japan). In addition, some of the residents who were known as the Hwachog and the Jaein in Korea plundered the Korean Peninsula under the identity of Wako. According to the history of Goryeo in 1383, the Hwachog and Jaein living in Gyoju-Gangneung Province pretended to be Japanese pirates and plundered Pyeongchang, Wonju, Yeongju,Sunheung, and Hoengcheon, among other regions.


The Hwachog typically engaged themselves in livestock farming, willow craft, and manufacture of leather products. The Jaein, on the other hand, were entertainment people who performed in mask plays and did acrobatics, and often they were discriminated to be the lower class in the Korean society. The residents (including those of Japanese nationality) in Geoje Island, the south eastern part of the Korean Peninsula, also joined the Wako. In the entry for the year 1369, the History of Goryeo states, the Wako plundered vessels in Yeongju, Onsu, Ryeosan, and Myeonju. Initially, the people of Wa, known as the“Waein”– and probably not the same as “Ilbonin”, which means the Japanese – proclaimed that they wanted to live in Geoje Island and intended to maintain a cordial relationship for a long time, which the authority of Goryeo believed in and permitted them to live there, but now they have plundered’

1555 wako invasions

In addition, horse breeders on Jeju Island probably joined the Wako because the Wako used many horses raiding inland across the land. It is possible that the horse breeders in Jeju had offered horses to the Wako. During the Mongol occupation of Korea in the 13th century, the Mongols transplanted Mongolian horse breeders to Jejuby calling them Mokho. After the translation from Yuan to Ming in China, they rebelled against Goryeo in 1374, after which the forces of Goryeo crushed them. There are no documents that reveal the nature of relations between the Mokho and the Wako. However, if this were true, there is a possibility that the Mokho and the Wako cooperated in the rebellion and we can assume that the Wako consisted of not just the Japanese, but peoples of diverse ethnic origins around East China Sea.


Based on the research of Takashi Kawato.
Some other good resources relating to the pirates can be found from factsanddetails.com and samurai archives.

Hazard, Benjamin H. “The Formative Years of The Wakō, 1223-63.” Monumenta Nipponica 22, no. 3/4 (1967): 260–77.

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