wakō, Chinese (Pinyin) wokou or (Wade-Giles romanization) wo-k’ou, any of the groups of marauders who raided the Korean and Chinese coasts between the 13th and 16th centuries. They were often in the pay of various Japanese feudal leaders and were frequently involved in Japan’s civil wars during the early part of this period.
In the 14th century Japanese feudal leaders began to send large trading expeditions to China and Korea. When denied trading privileges, the Japanese were quick to resort to violence to ensure their profits. By the 14th century, piracy had reached serious proportions in Korean waters. It gradually declined after 1443, when the Koreans made a treaty with various Japanese feudal leaders, permitting the entry of 50 Japanese trade ships per year, a number that was gradually increased.
Meanwhile, with the decline of central authority in China toward the end of the 13th century, piracy began to increase along the China coast. Using ships large enough to carry 300 men, the pirates would land and sometimes plunder whole villages.
Originally mainly Japanese, in later times the pirates were of mixed origin; by the early 16th century, the majority of them were probably Chinese. Basing themselves on islands off the Chinese coast, the pirates eventually made their main headquarters on the island of Taiwan, where they remained for over a century. By the end of the 17th century, with the growth of a strong central power in Japan under the Tokugawa shogunate (1603–1867) and in China under the Qing dynasty, most of the piracy was eliminated.