元寇
Tsushima was then an important trade center. 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.