Masuda clan

A powerful clan in Iwami Province. Its ancestor was Fujiwara no Kunikane, governor of Iwami Province, who settled in Ikamigo, Naka County (Hamada City, Shimane Prefecture) in the late Heian period and called himself the Mikamoto clan. It is said that in the generation of his great-grandson Kanetaka, he moved his base to Masuda-no-sho, Mino County (Masuda City) and called himself the Masuda clan. Kanetaka Masuda was appointed as the governor of Iwami Province by Minamoto no Yoritomo in 1184 (Genryaku 1), and is said to have ruled one third of the country, mainly in Mino County, but the historical document on which this is based is the "Lost Letter Draft" from the Nanboku-cho period, so caution is required in determining whether this is true. Historical records show that the name first became clear in the time of Masuda Kanesue. Throughout the Kamakura period, branch families such as the Misumi, Fukuya, and Sufu clans were sent out into the country, and they were also treated by the shogunate as vassals and had a strong sense of independence. There is also a theory that the Misumi clan was not a branch family, but was the head family of the Mikamimoto clan. During the civil wars of the Northern and Southern Courts period, the line of the Masuda head family died out, and a branch family member, Kanemi, inherited the family name. In 1383 (Kōwa 3/Eitoku 3), he received a letter of assurance from Ashikaga Yoshimitsu and the privilege of not entering the shugo (guardian) from Ouchi Yoshihiro, and thereafter belonged to the Ouchi clan. During the Onin War (1467-1477), the family expanded its influence by suppressing influential branch families and the Yoshimi clan, a lord of Iwami Province, among others. They were also closely related by marriage to the Sue clan, a senior vassal of the Ouchi clan, but when the Ouchi clan was destroyed during the reign of Fujikane in 1557 (Koji 3), they joined the Mori clan. His son, Masuda Motoyoshi, married the daughter of Kikkawa Motoharu of the Mori clan, and was given a fief of over 12,500 koku. He played an active role as a senior vassal of the Mori clan. After the Battle of Sekigahara, when the Mori clan was reduced to the two provinces of Bungo and Choshu, he moved to Susa in Nagato Province (Hagi City, Yamaguchi Prefecture) and was given a fief of over 6,200 koku (later reduced to 11,000 koku) and worked hard to rebuild the finances of the Hagi Domain (Choshu Domain). During the Edo period, he was a permanent elder retainer of the Hagi Domain. After the Meiji Restoration, he became a baron.

[Makoto Tatehana]

"History of Masuda City" by Yatomi Kumaichiro (1963, Masuda Local History Yatomi Society)" ▽ "Comprehensive Genealogy of the Bungo-Choshu Families in the Early Modern Period" (1966, Bungo-Choshu Newspaper Company)" ▽ "Hagi Clan Faction Records Volume 1" (1967, Yamaguchi Prefectural Archives) ▽ "Study of the Masuda Clan of Iwami Province" by Fukuda Eijiro (included in "Sengoku Daimyo Essays 6: Studies of Chinese Daimyo", 1984, Yoshikawa Kobunkan)" ▽ "The Masuda Clan and Susa - Permanent Elders of the Mori Clan" edited by Nishimura Takemasa (1997, Susa Town Board of Education)

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

石見国(いわみのくに)の豪族。平安後期、那賀(なか)郡伊甘郷(いかみごう)（島根県浜田市）に土着して御神本(みかもと)氏を称した石見国司(こくし)藤原国兼(ふじわらのくにかね)を祖とし、曽孫(そうそん)兼高(かねたか)の代より美濃(みの)郡益田荘(ますだのしょう)（益田市）に本拠を移して益田氏を称したと伝えられる。益田兼高は、1184年（元暦1）源頼朝(みなもとのよりとも)から石見国押領使(おうりょうし)に補任(ぶにん)され、美濃郡を中心に国内の3分の1を領したといわれるが、その論拠となる史料は南北朝期の「紛失状案」であり、事実とするには慎重を要する。史料上明確となるのは益田兼季(かねすえ)の代からである。鎌倉期を通じて三隅(みすみ)・福屋(ふくや)・周布(すふ)氏などの庶家を国内に分出し、彼らも御家人(ごけにん)として幕府に把握され、独立性が強かった。なお三隅氏は庶家ではなく、御神本氏の惣領家(そうりょうけ)にあたるという説もある。南北朝期の内乱過程で益田惣領家の系統はとだえ、庶家の兼見(かねみ)が名跡を継ぎ、1383年（弘和3・永徳3）足利義満(あしかがよしみつ)から安堵御教書(あんどみぎょうしょ)を、大内義弘(おおうちよしひろ)から守護不入(ふにゅう)の特権を得て、以後大内氏に属した。応仁(おうにん)の乱（1467～1477）を経るなかで、有力庶家や石見国衆吉見(よしみ)氏などを抑えて勢力を拡大、また大内家重臣の陶(すえ)氏とは姻戚(いんせき)関係にあり、密接な間柄にあったが、1557年（弘治3）藤兼(ふじかね)の代に大内氏が滅亡すると、毛利(もうり)氏に属した。その子益田元祥(もとよし)は、毛利一族の吉川元春(きっかわもとはる)の娘を妻として1万2500余石を領し、毛利家重臣として活躍、関ヶ原の戦い後、毛利氏が防長(ぼうちょう)2国に減封されると、長門国(ながとのくに)須佐(すさ)（山口県萩市）に移住して6200余石（のち1万1000石）を領し、萩(はぎ)藩（長州藩）の財政再建に尽力した。江戸期は萩藩の永代家老。維新後は男爵。

［舘鼻　誠］

『矢富熊一郎著『益田市史』（1963・益田郷土史矢富会）』▽『『近世防長諸家系図綜覧』（1966・防長新聞社）』▽『『萩藩閥閲録　第1巻』（1967・山口県文書館）』▽『福田栄次郎著「石見国益田氏の研究」（『戦国大名論集 6　中国大名の研究』所収・1984・吉川弘文館）』▽『西村武正編『益田氏と須佐――毛利藩の永代家老』（1997・須佐町教育委員会）』

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