Sō clan
On June 19, 1419, the recently-abdicated King Taejong of Joseon sent General Yi Jongmu to an expedition to Tsushima Island to clear it of the Wokou pirates, using a fleet of 227 vessels and 17,000 soldiers, known in Japanese as the Ōei Invasion. The Korean army returned to the Korean Peninsula on July 3, 1419, and Korea gave up occupation of Tsushima. In 1443, the Daimyo of Tsushima, proposed a Gyehae treaty. The number of trade ships from Tsushima to Korea was decided by this treaty, and the Sō clan monopolized the trade with Korea.