Sō Yoshitoshi

was a Sō clan daimyō (feudal lord) of the domain of Tsushima on Tsushima Island at the end of Japan's Sengoku period, and into the Edo period. His name is sometimes read as Yoshitomo. Under the influence of Konishi Yukinaga, he was baptized and accepted the name "Dario". He took part in Toyotomi Hideyoshi's invasions of Korea in the 1590s, and led a force in the Siege of Busan.

The Sō clan did not participate in the Battle of Sekigahara in 1600.

Early life Yoshitoshi was the fifth son of Sō Masamori. His wife, who took the baptismal name Maria, was the daughter of Konishi Yukinaga. Yoshitoshi became the head of the family in 1580, after his adoptive father, Sō Yoshishige, was defeated, and Tsushima conquered, in a prelude to Toyotomi Hideyoshi's Kyūshū Campaign.

In 1587, Toyotomi Hideyoshi confirmed the Sō clan's possession of Tsushima. ), had a vested interest in preventing conflict between Korea and Japan, and Yoshitoshi delayed talks (he was assigned to Hideyoshi's second mission to Korea, after the first one in 1587 had failed ) for nearly two years. After Hideyoshi renewed his demands and pushed Yoshitoshi to deliver his message, Yoshitoshi, rather than delivering Hideyoshi's demands, instead reduced the visit to the Korean court to a campaign to better relations between the two countries, and was able to secure a Korean diplomatic mission to Japan, which arrived in 1590. The message the Korean envoys received from Hideyoshi, redrafted as requested because it was too discourteous, invited Korea to submit to Japan and join in a war against China.

In 1603, Tokugawa Ieyasu established a new shogunate, and Sō Yoshitoshi was officially granted Fuchū Domain (100,000 koku) in Tsushima Province.

In the continuation of the diplomatic talks toward peaceful relations, Joseon in 1606 expanded its conditions and demanded that the shogun write a formal letter requesting peace, and to extradite the Japanese soldiers who had defiled the Joseon Royal Tombs near Hanseong. Realizing that the Shogunate would never agree to such a request, Sō Yoshitoshi sent a forged letter and a group of criminals instead. The great need to expel the Ming soldiers pushed Joseon into accepting and sending an emissary in 1608. The result was a return of Joseon prisoners and the restoration of diplomatic and trade relations between the two countries.

Yoshitomo's descendants held this domain until the abolition of the han system.

In 1884, the head of this clan line was ennobled as a "Count".