In the late 16th century, Japanese leader Toyotomi Hideyoshi united the various feudal lords (daimyō) under his command. Planning to unite all factions with a common cause, Hideyoshi's coalition attacked Joseon Korea, leading to the Japanese invasions of Korea (1592–1598). Tsushima was the main naval base for this invasion, and in continuing support of the war, large numbers of Korean prisoners were transported to Tsushima until 1603.