Wokou Wokou ( ; Japanese : わこう " Wakō " ; Korean : 왜구 " Waegu " ) , which literally translates to " Japanese pirates " or " dwarf pirates " , were pirates who raided the coastlines of China and Korea . Wokou came from a mixture of ethnicities . The term Wokou is a combination of " Wō " ( 倭 ) referring to " dwarves " or Japanese , and " kòu " ( ) , meaning " bandit " . History . There are two distinct eras of " wokou " piracy . The early wokou mostly set up camp on Japanese outlying islands , as opposed to the 16th century wokou who were mostly non - Japanese . The early wokou raided the Japanese themselves as well as China and Korea . Records report that the main camps of the early wokou were the island of Tsushima , Iki Island , and the Gotō Islands . Jeong Mong - ju was dispatched to Japan to deal with the problem , and during his visit Kyushu governor Imagawa Sadayo suppressed the early wokou , later returning their captured property and people to Korea . In 1405 Ashikaga Yoshimitsu sent twenty captured pirates to China , where they were boiled in a cauldron in Ningbo . According to the " History of Ming " , 20 % of the 16th century wokou were Ryukyu and 10 % " other " , with the remaining 70 % being ethnic Chinese . Notable wokou included the Chinese pirate Wang Zhi , and King Myeongjong of Joseon punished a Chinese wokou for pretending to be Japanese . Korea launched attacks on pirate bases on Tsushima in 1419 with the Gihae Eastern Expedition . General Yi Jongmu ' s fleet of 227 ships and 17 , 285 soldiers set off from Geoje Island toward Tsushima on June 19 , 1419 . The routes of the Korean attack were guided by captured Japanese pirates . After landing , General Yi Jongmu first sent captured Japanese pirates as emissaries to ask for surrender . When he received no reply , he sent out his forces and the soldiers proceeded to raid the pirates and destroy their settlements . The Korean army destroyed 129 boats , 1939 houses and killed or enslaved 135 coastal residents as well as rescueing 131 Chinese and Korean captives of the pirates and 21 slaves on the island . The number of Wokou raids dropped dramatically since the Korean expedition . Two well known Chinese military figures involved in the combating of Wokou are Qi Jiguang and Yu Dayou . Yu Dayou was a general of the Ming Dynasty who studied martial arts in a shaolin temple and who was assigned to defend the coast against the Japanese pirates . In 1553 , a young man named Qi Jiguang became Assistant Regional Military Commissioner of the Ming Dynasty and was assigned to " punish the bandits and guard the people " which meant taking on the Japanese pirates attacking the Ming east coast . At the time he was only twenty - six years old . On the eve of the next year he was promoted to full Commissioner in Zhejiang because of his successes . Because of the extent of corruption in the Ming Dynasty , many Chinese officials actually had relations with the pirates and benefited from the piracy , making it difficult for central authorities to control . Some of the coastal forts built for defense against Wokou can still be found in Fujian . Among them is the well - restored Chongwu Fortress in Chongwu Town , Huai ' an County , and the ruins of the Liu ' ao Fortress in Liu ' ao , Zhangpu County . Controversy over identity . The identity of the wokou is subject to some debate , with various theories about the ethnic makeup and national origin of the pirates . Professor Takeo Tanaka of University of Tokyo proposed in 1966 that the early wokou were Koreans living on these outlying islands . In the " Annals of the Joseon Dynasty " , Korean historian " Sejong Sillok " ( Hangul : ; Hanja : ) , Sunmong Lee wrote , " I hear that in the late period of the Goryeo Dynasty , Wokou were roaming over this land [ Joseon ] and peasants could not stand against them . However , even though only 1 or 2 out of 10 incidents were caused by real Japanese ( Hangul : 왜인 , Hanja : 倭人 ) , some of our peasants wore the clothes of Japan , formed a group and caused trouble . . . in order to stop all evils , there is nothing more urgent than " Hopae " ( a Goryeo word meaning ' personal identification ' ) . " However , Lee did not live during the Goryeo Dynasty , and was likely relating rumor or legend as opposed to solid documented evidence . Moreover , the main body of Lee ' s record concentrates on how national security was deteriorating and how it required special attention ; it is possible he made use of unreliable information to support his point . Lee ' s assertion is therefore not highly valued as a source for wokou by other researchers . Some Goryeo records also indicate that only 0 . 57 % ( 3 of 529 ) of 14th century Wokou incidents were non - Japanese in origin . In China , in contrast , 100 % of ships named as pirates were captained by Chinese . One Chinese source states that none of the early wokou were ethnic Japanese , but Southern Chinese and other foreigners with whom the Chinese traded . The current prevailing theory , is that of Shōsuke Murai , who demonstrated in 1988 that the early wokou came from multiple ethnic groups rather than one singular nation . Murai claimed that the wokou were " marginal men " living in politically unstable areas without national allegiances , akin to the Zomia thesis . Supporters of this theory point out that one of the early wokou leaders , Ajibaldo , was variously claimed by period sources to be Mongolian , Japanese , Korean , and an " islander " ; his name is apparently Korean and Mongolian in origin . Wokou activity increased during the Sengoku period civil war , when Japan was unable to control its ports . Literature . Primary sources : Secondary sources :