was a misunderstanding) and the Ryukyus. As for the military preparations, the construction of as many as 2,000 ships may have begun as early as 1586. To estimate the strength of the Korean military, Hideyoshi sent an assault force of 26 ships to the southern coast of Korea in 1587. On the diplomatic front, Hideyoshi began to establish friendly relations with China long before he had completed the unification of Japan. He also helped to police the trade routes against the wokou. Diplomatic dealings between Japan and Korea In 1587, Hideyoshi sent his first envoy Yutani Yasuhiro, to Korea, which was during the rule of King Seonjo, to re-establish diplomatic relations between Korea and Japan (broken since the Wokou raid in 1555). Hideyoshi hoped to use as a foundation to induce the Korean court to join Japan in a war against China. Yasuhiro, with his warrior background and an attitude disdainful of the Korean officials and their customs, failed to receive the promise of future ambassadorial missions from Korea. Around May 1589, Hideyoshi's second embassy, consisting of Sō Yoshitoshi (or Yoshitomo, 柳川調信),宗義智 Yanagawa Shigenobu, and Buddhist monk Genso (玄蘇) reached Korea and secured the promise of a Korean embassy to Japan in exchange for a group of Korean rebels which had taken refuge in Japan. In 1587, Hideyoshi had ordered the adopted father of Yoshitoshi and the daimyō of Tsushima Island, Sō Yoshishige,宗義調 to offer the Joseon Dynasty an ultimatum of submitting to Japan and participating in the conquest of China, or facing the prospect of open war with Japan. However, as Tsushima Island enjoyed a special trading position as the single checkpoint to Korea for all Japanese ships and had permission from Korea to trade with as many as 50 of its own vessels, the Sō family had a vested interest in preventing conflict with Korea, and delayed the talks for nearly two years. Even when Hideyoshi renewed his order, Sō Yoshitoshi reduced the visit to the Korean court to a campaign to better relations between the two countries. Near the end of the ambassadorial mission, Yoshitoshi presented King Seonjo a brace of peafowl and matchlock guns – the first advanced firearms to come to Korea. Ryu Seong-ryong, a high-ranking scholar official, suggested that the military put the arquebus (a matchlock firearm) into production and use, but the Korean court failed to appreciate its merits. This lack of interest