Gyehae Treaty
Under Sejong, Joseon concluded an agreement with the lord of Tsushima limiting trade with Japan to 50 ships and 200 seok of rice a year.
Joseon’s foreign policy was sadae gyorin — “serving the great and befriending neighbours”. It sent regular and special tribute missions to Ming, while toward the Jurchens and Japan it combined force with conciliation. Against the Jurchens it opened the Four Commanderies and Six Garrisons, but also gave posts and land to those who submitted and opened trading posts at Gyeongseong and Gyeongwon. In Hanyang it kept the Taepyeonggwan for Ming envoys, the Bukpyeonggwan for Jurchens and the Dongpyeonggwan for the Japanese.
After striking the pirates’ base in the Tsushima expedition (1419), Joseon in 1426 added Yeompo (Ulsan) to Busanpo (Dongnae) and Jepo (Ungcheon), opening the Three Ports with Japanese houses (waegwan) for trade. As traffic grew, the Gyehae Treaty of 1443 limited Tsushima to 50 trading ships and 200 seok of rice a year. The growing number of Japanese settled in the Three Ports led to the Three Ports Revolt of 1510.
