Koyumi Shogun - Oyumi Kubo

Japanese: 小弓公方 - おゆみくぼう

…In the late Eisho era (1504-21), he came into conflict with his father Masauji, returned to secular life, and took the name Yoshiaki. Shortly thereafter, he adopted the religious name Dotetsu. He was supported by the Takeda clan of Kazusa, and seized Oyumi Castle, the residence of the Shimousahara clan. From there he expanded his influence into Shimousa, Kazusa, and Awa, and was given the honorific title of Oyumi kubō. Later, he came into conflict with Ashikaga Takamoto, the Koga kubō, who feared his expansion, and in the days of his son Haruuji, he was defeated and killed in 1538 at Kōnodai in Shimousa by the forces of Hōjō Ujitsuna, who was ordered by Haruuji. …

From Mr. Satomi

...In 1533 (Tenbun 2), Yoshimichi's son Yoshitoyo killed his uncle Sanetaka after a power struggle, but Sanetaka's legitimate son Yoshitaka defeated Yoshitoyo the following year, avenging his father and becoming head of the Satomi clan. At the time, the Koga kubō family held traditional authority over the generals of the Kanto region, and there was conflict between the kubō Ashikaga Takamoto and his younger brother Yoshiaki. In 1517 (Eishō 14), Yoshiaki based himself in Koyumi Castle in Shimousa (present-day Minami Omimachi, Chiba City) and called himself Koyumi kubō. In 1538, Hojo Ujitsuna and Ujiyasu, father and son, allied with the Koga kubō, advanced into Shimousa and defeated Yoshiaki's army at Kōnodai (present-day Ichikawa City), killing Yoshiaki and destroying the Koyumi kubō. ...

From Shimousa Province

…
[Battle of Konodai]
After that, the power of the Later Hojo clan, replacing the Uesugi clan, advanced from Izu and Sagami to Musashi. The Koga kubō, Ashikaga Takamoto (grandson of Shigeuji), relied on the Hojo clan of Mame-sa and the Chiba and Hara clans of Shimousa, but Takamoto's younger brother Yoshiaki was supported by the Takeda clan of Kazusa and the Satomi clan of Awa, and in 1517 (Eishō 14) he defeated the Hara clan at Oyumi Castle (Minami-Oyumi, Chiba City) and based himself there, calling himself the Oyumi kubō (Oyumi Imperial Palace) and aiming to unify the Kanto region in place of the Koga kubō. Takamoto's son Haruhisa became the son-in-law of Hojo Ujitsuna, and allied with the Later Hojo clan to oppose the Oyumi kubō, which led to the first Battle of Konodai in 1538 (Tenbun 7).

*Some of the terminology explanations that refer to "Koyumi Shobo" are listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

Japanese:

…永正年代(1504‐21)後期には父政氏と対立し，還俗して義明と称し，その後まもなく道号道哲を称した。彼は上総武田氏に擁立されて，下総原氏の居城小弓（おゆみ）城を奪取し，同城を拠点に下総，上総，安房に勢力を伸張し，小弓公方と尊称された。後に勢力拡大を恐れた古河公方足利高基と対立し，その子晴氏のとき，1538年下総国府台（こうのだい）で晴氏の命を受けた北条氏綱の軍勢と戦って敗死した。…

【里見氏】より

…33年(天文2)義通の子義豊は叔父実尭と勢力争いの末これを殺したが，実尭の嫡子義尭は翌年義豊を滅ぼして父の仇を討ち，里見氏の主となった。　当時関東の諸将に対し伝統的権威を保持していた古河公方家では，公方の足利高基と弟義明とが対立していたが，義明は1517年(永正14)下総小弓城(現，千葉市南生実町)に拠り小弓公方と称した。38年古河公方と結んだ北条氏綱･氏康父子が下総に進撃，国府台（こうのだい）(現，市川市)で義明軍を破り，義明は討死して小弓公方は滅びた。…

【下総国】より

…
［国府台合戦］
　その後，上杉氏に代わって後北条氏の勢力が伊豆･相模から武蔵へと進出する。古河公方足利高基(成氏の孫)は豆相の北条氏や下総の千葉，原氏らを頼んだが，高基の弟義明は上総武田氏や安房里見氏に支持され，1517年(永正14)小弓（おゆみ）城(千葉市南生実（おゆみ）)の原氏を討ってこれに拠り，小弓公方(小弓御所)と称し，古河公方に代わり関東の統一を志した。高基の子晴氏は北条氏綱の娘婿となり，後北条氏と同盟して小弓公方と対抗し，38年(天文7)第1次国府台合戦が起こる。…

※「小弓公方」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典第２版について | 情報

<<: Koyumi Imperial Palace - Oyumigosho

>>: Oyudonoue - Oyudonoue