Mitoya Clan (三刀屋氏)

The Mitoya clan was one of Japanese clans. Among several branches of the Mitoya clan, the most famous one is the Mitoya clan, which claimed descent from a branch of Seiwa-Genji (the Minamoto line descended from Emperor Seiwa), a MINAMOTO no Mitsuyoshi line, Shinano Genji, and which bore the name of Mitoya after they settled in Izumo Province.

Suwabe Mitoya clan

Tradition has it that Mitoya clan was descended from a branch of Seiwa-Genji, a line of MINAMOTO no Mitsuyoshi, Ina clan. MINAMOTO no Tametomo, great grandson of Mitsuyoshi, went down to Shinano as Governor of Shinano Province, where his son, Tamesuke INA, who took the family name of Ina, became the progenitor of Shinano-Genji. Sachisuke, grandson of Tamesuke, bore the name of SUWABE, whose descendant was hired as a manager and lord of manor in the Mitoya-go district in Iiishi-gun County of Izumo Province and moved to Izumo, and took the placename Mitoya as his family name, which was considered to be the beginning of the Mitoya clan.

Sukenaga SUWABE, who worked hard in the Jokyu War on the side of the feudal government headed by a shogun, was hired as the manager and lord of manor in Mitoya-go district and travelled there in 1221. In the middle of the Kamakura period, as the Hojo clan's power grew even larger, many immediate vassal of the shogun went down to the provinces where they owned territories. Most of the clans, who later accomplished territorial lords during the period of Warring States and warlords, went down to the provinces during this period (for example, the Mori clan and the Yoshikawa clan). The Mitoya clan, which was not an exception to this trend, prepared for the forthcoming period of Warring States headquartered in Mitoya-go district in Izumo Province.

In 1335 after the Kenmu Restoration, when Takauji ASHIKAGA raised, in Kamakura, his standard of establishment of samurai government, Tadayoshi ASHIKAGA urged Sukeshige MITOYA, the head of Mitoya clan, to send an army. As Takasada ENYA, the military governor of Izumo Province, took the side of Takauji ASHIKAGA, Sukeshige also belonged to the side of Takauji and fought in the north central region where he participated in the battle of reducing Kanagasakijo Castle as well as suppressing of Akiie KITABATAKE in Mino Province in 1337. When Takasada ENYA was defeated by a rebellion afterward, Mitoya clan came under the umbrella of the influential Yamana clan. During the Meitoku War started by Mitsuyuki YAMANA in 1391, the Mitoya clan seceded from the Yamana clan and participated in the punitive force against it under the command of the government headed by a shogun.

After the Yamana clan perished, the Mitoya clan raised the army with Takanori KYOGOKU, who became the new shugo, and defeated the remnants of Yamana clan. Thereafter, the Mitoya clan became the vassal of the Kyogoku clan and was strongly influenced by the Amago clan, the deputy provincial constable. During the Onin War broke out in 1467, as Mochikiyo KYOGOKU, the constable in Izumo Province, took Hosokawa's side, Tadasuke MITOYA went to Kyoto and fought Yoshikado SHIBA, which was on Yamana's side. The Yamana clan fought on successive fronts to Omi Province in the next year and fought with the Rokkaku clan.

Meanwhile in Izumo Province, shugodai Kiyosada AMAGO had suppressed local rebellions to grow as influential as the Kyogoku clan, its master's house. Then, Tsunehisa AMAGO started to move up the ladder from the deputy constable to the feudal lord during the Sengoku period. In 1484, the bakufu commanded that the punitive force be dispatched against Tsunehisa AMAGO, which was joined by the Mitoya clan. When Tsunehisa AMAGO, who was once under house arrest, rose again by stratagem, Tadasuke returned his allegiance to Tsunehisa AMAGO.

The Ouchi clan was the supreme ruler in the western part of the mainland of Japan during this period. In 1507, together with the Amago clan, the Mitoya clan joined the army for Kyoto headed by Yoshinori OUCHI who served the previous shogun, Yoshitane ASHIKAGA, but Tsunehisa AMAGO returned home earlier than others from the battle in Kyoto which had been drawn into a war, began invading Ouchi's territory where Yoshinori was absent for the war, starting their confrontation with the Ouchi clan. Yorisuke MITOYA fought on successive fronts through Iwami Province to Aki Province following Tsunehisa AMAGO and achieved meritoriious services on the field of battle. The legitimate son of Yorisuke was Hisasuke MITOYA.

In 1540, the Amago clan raised an army to defeat Motonari MORI, who had expanded the sphere of influence in Aki Province. During the Yoshida Koriyamajo Castle War, Hisasuke participated as a warlord on the side of the Amago clan, but was soundly defeated and fled to Izumo. The Mitoya clan surrendered to the Ouchi clan, and then, after the war of Gassantodajo Castle, again served the Amago clan. Together with Haruhisa AMAGO, the Mitoya clan had several battles against the Mori clan, which inherited Ouchi's territory, but during the time of Yoshihisa AMAGO, Hisasuke surrendered to the Mori clan together with Tamekiyo MISAWA. When the Mori clan began invading Izumo in 1562, Mitoyajjo Castle served as the base for war supplies for the Mori force, as the castle was a strategic point connecting the place in the shade of the mountain and the south side of the mountain. Accordingly, the Mitoya clan was attacked by the Amago clan, but fought off the Amago forces with reinforcements by Takaie SHISHIDO and Takamichi YAMAUCHI. Again in 1563, the Amago clan ordered Hisakane UYAMA, Yoshikiyo USHIO, and Hisatsuna TACHIHARA to attack the Mitoyajo Castle, but were fought off. In 1565, the Mitoya clan took part in the attack on the Gassantodajo Castle, which was the main castle of Amago clan, responsile for occupying the Sugaya-guchi entrance together with the Takakage KOBAYAKAWA's army.

After the Amago clan collapesed, the army for restoring the Amago clan headed by those including Yukimori YAMANAKA began to operate actively in Izumo Province. Hisasuke did not participate in the restoration army, and presented written vows to Motoharu KIKKAWA to show that he harbored no treacherous designs. In 1573, he was involved in appointing the head priest of the Tendai sect and was granted the rights of using the things including the felt saddle-blanke) and the bag for keeping a bow by the Emperor Ogimachi.

He further fought on successive fronts as the Mori clan expanded its sphere of influence. He also participated in the Battle of Kozukijo Castle in 1578 and witnessed the end of the Amago clan.

When the Mori clan became subordinate to Hideyoshi TOYOTOMI, who had seized power after the death of Nobunaga ODA, Hisasuke was ordered to participate in the project to unify the country, which was headed by Hideyoshi and fought on successive fronts across Kyushu.

Hisasuke met Ieyasu TOKUGAWA in 1586 when he attended Terumoto MORI, Hiroie KIKKAWA, and Takakage KOBAYAKAWA as they visited Kyoto; that raised Terumoto MORI's suspicions about Hisasuke MITOYA, who was expelled from the land of Izumo. Since no documents proving that Hisasuke visited Kyoto or met Ieyasu exists, Hisasuke was supposed to be expelled by Terumoto, who had strengthened control over his retainers and had ambitions to own Mitoya which was a strategic point. In 1588, Hisasuke left Mitoya and lived in seclusion in Kyoto. Although Ieyasu TOKUGAWA invited Hisasuke to enter government service for 8,000 koku, Hisasuke declined the offer; and he died in Yokkaichi, Kyoto.

Takasuke MITOYA, the legitimate son of Hisasuke, served the Mori clan and fought in Korea in the Mori's force during the Bunroku-Keicho War. Takasuke was short of recovering his fief Mitoya, and left the Mori clan to be a vassal of the Hosokawa clan; during the Battle of Sekigahara in 1600, he joined the army locking itself up in Tanabejo Castle in Tango Province and where he provided exemplary service. Afterwards, he left the Hosokawa clan and served the Kishu Tokugawa family for 3000 koku. Sukeaki, son of Takasuke MITOYA, returned his family name to the original Suwabe, which was the end of the Mitoya clan.

Summary of Mitoya clan
Chronicle List of heads of Mitoya clan