was a Japanese clan claiming descent from Taira no Tomomori. The clan governed and held Tsushima Island from the 13th through the late 19th century, from the Kamakura period until the end of the Edo period and the Meiji Restoration.
In 1587, Toyotomi Hideyoshi confirmed the clan's possession of Tsushima. In the struggles which followed Hideyoshi's death, the clan sided with the Tokugawa; however, they did not participate in the decisive battles which preceded the establishment of the Tokugawa shogunate. The descendants of tozama Sà  Yoshitoshi (1568âÂÂ1615) remained at Tsushima-Fuchà « Domain (100,000 koku) in Tsushima Province until the abolition of the han system. The head of this clan line was ennobled as count in 1884.
Historians consider the Sà  clan to have been an offshoot of the Koremune clan, who served as local officials of Dazaifu and Tsushima Province. The earliest evidence of Sà  clan cohesion arises in the 11th century. The Koremune had their start as governors of Tsushima following an incident in 1246, when the Abiru clan, local district officials (zaichà Âkanjin) on Tsushima, rebelled against the Chinzei Bugyà  and the Dazaifu government that governed all of Kyà «shà « and the surrounding regions on behalf of the Kamakura shogunate. Dazaifu ordered Koremune Shigehisa to stop the rebellion and to destroy the Abiru clan. The Shà Âni clan, the shugo 'governors' of Tsushima, rewarded him for his victory with the post of jità  'local land steward'.
The Koremune extended its influence on Tsushima over the course of the Kamakura period, as the deputies of the Shà Âni. When the Mongols invaded Japan in 1274, clan head Sà  Sukekuni fought against the invaders and died on Tsushima. The Sà  clan fought for the Shà Âni clan and for the Ashikaga's Northern Court during the Nanboku-chà  period (1336âÂÂ1392), and seized a portion of Chikuzen Province. Imagawa Ryà Âshun became Chinzei Tandai (head of the Dazaifu government) soon afterwards, and the Imagawa clan became shugo of Tsushima. When Imagawa Ryà Âshun was dismissed from his post in 1395, Sà  Sumishige became shugo of Tsushima.
Though now holding the hereditary post of shugo of Tsushima, the clan remained vassals of the Shà Âni until the late 15th century. In the course of breaking away from the Shà Âni clan, the Sà  clan started to claim that it originated with a grandson of Taira no Tomomori, Taira no Tomomune. The Sà  clan moved its base from northern Kyushu to Tsushima around 1408. Although it struggled to keep its territory in Chikuzen on Kyushu, the clan was finally purged from that region by the à Âuchi clan in the mid-15th century.
Alongside the Shà Âni clan, whose hereditary clan heads now regularly operated under Sà  clan guidance, the Sà  fought the à Âuchi numerous times across the Sengoku period (1467âÂÂ1600), and later the Mà Âri and à Âtomo clans as well; the clan lost and regained their territory in Chikuzen province on Kyushu many times over the course of the period. In the end, the downfall of the Shà Âni, marked by Shà Âni Fuyuhisa's 1559 defeat at the hands of Ryà «zà Âji Takanobu, brought an end to the Sà  clan's territorial aspirations on Kyushu.
Following a period of increased wokou predation, the Joseon-Japanese "Treaty of Tenbun" in 1547 (Tenbun year 11) limited trading to the Joseon port of Busan and also limited SÃ Â clan commerce to 20 ships annually.
The SÃ Â clan submitted to Toyotomi Hideyoshi in 1587 and supplied troops for the invasions of Korea during the Imjin War. The SÃ Â sided with the Western Army of Ishida Mitsunari at the Battle of Sekigahara (1600), yet they were not punished by Tokugawa Ieyasu. The prevalent theory is that Ieyasu sought to improve relations with Korea and China, and therefore pardoned the SÃ Â clan, which had a diplomatic channel with Korea.
The tozama SÃ Â clan were allowed to continue to rule Tsushima. Tsushima and the area around Tashiro in Hizen Province were included in the clan's fief (han), rated as worth 100,000 koku for its diplomatic and economic importance, though its agricultural production was actually under 30,000 koku per year. After the clan resumed diplomatic relations with Korea, the Tokugawa shogunate entrusted it with conducting diplomatic negotiations and trade with Joseon.
After the abolition of the han system in 1871, the last known head of the clan, SÃ Â Shigemasa (Yoshiaki), was made Governor of Izuhara Prefecture, the renamed Tsushima Province.
From roughly the 1430s to the 1550s, the clan worked towards independence, its sights set on gaining true control of Tsushima, and on establishing friendly relations with Joseon dynasty, Korea. The first of these goals was attained through a reversal of fate in which the Shà Âni came to rely upon the Sà  for military aid against the à Âuchi. Sà  Sadamori and his younger brother Sà  Morikuni helped to defeat the à Âuchi over ten times, and in doing so deepened their clan's relationship with the traders and merchants of Hakata, one of Kyushu's major ports. However, with the ultimate defeat of the Sà  clan by the à Âuchi clan, the latter became the dominant trading partner with Korea, often emphasizing on their shared heritage (à Âuchi claimed descent of a Paekche prince). Though not to the same extent, the Sà  family maintained an amicable relationship with Korea too despite the lack of a favorable framework like the à Âuchi, even though they themselves were also of Korean descent (through its parent clan, the Koremune clan and its own parent clan, the Hata clan which originates in Silla).
Being based on the mountainous island, the Sà  clan heavily relied on trade with Korea. Fortunately, the Sà  clan shared mutual interests with the Joseon Dynasty. In 1443, the Daimyà  of Tsushima, proposed the Gyehae treaty. The number of trade ships from Tsushima to Korea was decided by this treaty, and the Sà  clan monopolized the trade with Korea. The Sà  were required to greatly reduce the number of pirate attacks on Korea, and in return would be granted a virtual monopoly on Japanese trade with their neighbors on the peninsula. This would later lead to the emergence of the Sà  as one of the major clans in Japan, their wealth and power from trade more than making up for their small territory and submissive position vis-a-vis Korea.
The clan participated in the Japanese invasion of Korea. However soon afterwards, the clan took it upon themselves to repair relations with Korea, sending a number of envoys under the guise of being official shogunal envoys. In doing this, the clan sought to improve their position with both the shogunate and Korea. There is evidence that they embellished official documents to make themselves look better to the other.