Sō Yoshishige

Yoshishige Sō was a Sengoku-period feudal lord who served as shugo daimyo (military governor) of Tsushima Province. He was the seventeenth leader of the Sō clan.

Sō Yoshichika, born 1532 as firstborn son of Sō Haruyasu (the 16th head of the family), received his name from Ashikaga Yoshiharu (the 12th shōgun of Muromachi) in November 1542, when he was given the first character of his name, Yoshichika. In 1553, he succeeded his father as head of family (the 17th generation) and was given another character of his name from Ashikaga Yoshifuji (the 13th shōgun of Muromachi, known as Yoshiteru), reaffirming the connection of the family with the Sōn through the common character yoshi held by all members of the Sō Clan. He took an active role supporting the Kingdom of Joseon in suppressing Japanese incursions against its territory in 1555 (the Japanese Incursion of Ikuto), and in 1557 concluded the Jeongsi Treaty with Joseon which greatly expanded the amount of governmental trade conducted with Joseon and helped the Sō Clan become very prosperous. He also put down a rebellion on Iki Island in 1559 that started as a coup led by Tsuna Shigechika and others and confirmed the strongest authority of Mune Yoshichika and the Sō Clan over all other families in the area surrounding Katsuura.^[2]

Yoshichika retired from full service to the family in August 1566 and transferred authority to his adopted son, Sō Shigehisa, although he maintained a significant role in political matters. After the untimely deaths of Shigehisa and his younger brother Yoshizumi, Yoshichika acted as the guardian for Akikage (later known as Sō Yoshitomo), who became the head of the family when his other brothers were deceased. Yoshichika returned to the political scene during Toyotomi Hideyoshi's invasion of Kyushu in 1587.^[3]