The private trade started between Goryeo, Tsushima, Iki, and Kyūshū, but halted during the Mongol invasions of Japan between 1274 and 1281.
The Goryeosa, a history of the Goryeo dynasty, mentions that in 1274, an army of Mongol troops that included many Korean soldiers killed a great number of Japanese on the islands.
In 1389, General Pak Wi (朴威) of Goryeo attempted to clear the island of Wokou pirates, but uprisings in Korea forced him to return home.
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 daimyō of the So clan of Tsushima island was granted rights to conduct trade with Korea in fifty ships per year, in exchange for receiving a substantial stipend from the Korean government and aiding to stop any Japanese coastal pirate raids on Korean ports.