Nitta clan - Nittauji

A powerful clan in Kozuke Province (Gunma Prefecture). Seiwa Genji. Its ancestor was Yoshishige, the grandson of Minamoto no Yoshiie. At the end of the Heian period, Yoshishige developed the land of Nitta-gun, Kozuke Province (present-day parts of Ota City, Isesaki City, and Midori City), donated it to Fujiwara Tadamasa, and became the lower-ranking official of Nitta-no-sho, and his family exerted their influence within Nitta-no-sho. In addition to the main family, which was centered in Yura-go, the Iwamatsu, Serata, and Wakiya clans flourished in Nitta-sho, the Yamana and Satomi clans in western Gunma, and the Oida and Toriyama clans in Tsuma-no-sho, Echigo Province. The Nitta clan was treated coldly by the shogunate during the Kamakura period, but in 1333 (Genko 3/Shokei 2) they seized Kamakura in response to Emperor Godaigo's orders, and many of their family members were appointed as kokushi and shugo in various regions. During the civil war between the Northern and Southern Courts, the clan split into two factions: the Wakiya, Oida, Odate, and Horiguchi clans, who sided with Yoshisada on the Southern Court side, and the Iwamatsu, Yamana, and Satomi clans, who sided with the Ashikaga side. Nitta-sho fell under the control of the Iwamatsu clan. After Yoshisada's defeat and death in 1338 (Engen 3, Ryakuo 1), the clan continued to exert influence in Echigo and Kozuke under the leadership of his son Yoshioki, but gradually declined after Yoshioki's death in 1358 (Shohei 13, Enbun 3). The Iwamatsu clan, who controlled Nitta-sho, lived in Kanayama Castle, but during the reign of Mitsuzumi, they sided with Uesugi Zenshu in the Rebellion (1416-17) and were defeated, and eventually lost control to their vassal, the Yokose (Yura) clan. The Yura clan also claimed to be descendants of the Nitta clan, and so when it came to being included in the nobility after the Meiji Restoration, the Iwamatsu clan and the Yura clan fought over who would be allowed to join the nobility.

[Chijiwa Toru]

"The Fundamental Historical Materials of the Nitta Clan, by Kazumi Chiji (1974, Kokusho Kankokai)"

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

上野国(こうずけのくに)（群馬県）の豪族。清和源氏(せいわげんじ)。源義家(みなもとのよしいえ)の孫義重(よししげ)を祖とする。平安時代末、義重は上野国新田郡(にったごおり)の地（現在の太田市、伊勢崎市とみどり市の各一部）を開発、藤原忠雅(ただまさ)に寄進して新田荘(にったのしょう)下司(げし)となり、その一族は新田荘内に勢力を張る。由良郷(ゆらごう)を中心とした本宗家のほか、岩松(いわまつ)・世良田(せらた)・脇屋(わきや)氏らが新田荘内で、また山名(やまな)・里見(さとみ)氏は西上野を、大井田(おおいだ)・鳥山(とりやま)氏は越後国(えちごのくに)妻有荘(つまりのしょう)を本拠として一族は発展した。新田氏は鎌倉時代には幕府から冷遇されたが、義貞(よしさだ)の代、後醍醐天皇(ごだいごてんのう)に応じて1333年（元弘3・正慶2）鎌倉を攻め落とし、その功で一族の多くが各地の国司(こくし)・守護に任ぜられた。南北朝内乱期には、義貞とともに南朝方に属した脇屋・大井田・大館(おおだち)・堀口(ほりぐち)氏らの一族と、足利(あしかが)方に属した岩松・山名・里見氏らとに分裂、新田荘は岩松氏の支配に属す。1338年（延元3・暦応1）義貞の敗死後も子義興(よしおき)を中心に越後・上野に勢いを振るうが、1358年（正平13・延文3）義興の死後、しだいに衰えていった。新田荘を支配した岩松氏は、金山城(かなやまじょう)に居住するが、満純(みつずみ)のとき上杉禅秀(うえすぎぜんしゅう)の乱（1416～17）に与同して敗北、やがて家臣の横瀬(よこせ)（由良）氏に支配権を奪われてゆく。由良氏も新田氏の末裔(まつえい)と称し、ために、明治維新後に華族に列せられるに際しては、岩松氏と由良氏とが争うこととなった。

［千々和到］

『千々和実著『新田氏根本史料』（1974・国書刊行会）』

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