Iga clan

A powerful clan in the eastern provinces of the Middle Ages, and a bureaucrat in the Kamakura Shogunate. The Fujiwara clan of the Hidesato line. They were low-ranking officials in the Kurodo-dokoro (Kurodokoro) office, but Fujiwara Tomomitsu was appointed Iga no Kami on March 19, 1210 (Shogen 4), and they began to call themselves Iga clan members. Tomomitsu followed Minamoto no Yoritomo from the establishment of the Kamakura Shogunate, and achieved many military feats as a senior retainer of the Shogunate. In 1219 (Jokyu 1), Tomomitsu's son Iga Mitsusue went to Kyoto as the protector, but in 1221, he was attacked by the army of the retired Emperor Go-Toba during the Jokyu War and committed suicide. Asamitsu's daughter became the consort of the shogunate regent Hojo Yoshitoki, but after Yoshitoki's death in 1224 (Gennin 1), Hojo Masako suspected that she had conspired with her brother, the shogunal regent Iga Mitsumune, to make her son Masamura the regent and her son-in-law Ichijo Sanemasa the shogun, thereby seizing real power in the shogunate. Asamitsu's daughter was the consort of the shogunal regent Hojo Yoshitoki, but after Yoshitoki's death in 1224 (Gennin 1), Hojo Masako suspected that she had conspired with her brother, the shogunal regent Iga Mitsumune, to make her son Masamura the regent and to make her son-in-law Ichijo Sanemasa the shogun, and the Iga clan was wiped out from the shogunate. This was thought to have been a ploy by Masako to prevent her own power from declining due to the change of generations. The Iga clan was pardoned after Masako's death, and after they returned to the shogunate, they continued to play an important role in government affairs as shogunate officials for generations, and after Mitsumasa was transferred from the Kanto Council of Ministers to the Rokuhara Council of Ministers in 1275 (Kenji 1), the clan also moved their main base of operations to Kyoto. Their main territories were spread across the provinces of Mutsu, Hitachi, Musashi, Kai, Shinano, Wakasa, Bizen, Tajima, and Chikuzen, and their residences were in Kamakura and Kyoto. During the Kenmu government, Kanemitsu was a favorite vassal of Emperor Godaigo, and Sadanaga became the second Hikitsuke of the Oshu Shogunate. Morimitsu, the adopted son of Mitsusada, the guardian of Bizen Province at the end of the Kamakura period, moved north to Yoshishima Manor in Mutsu Province during the turbulent period of the Northern and Southern Courts, becoming a local lord, and serving on the side of the Ashikaga clan, he was appointed as the Tokaido Kendanshiki. His descendants took the name Iino from the name of the village within the manor, and the Iino Family Documents, a nationally designated Important Cultural Property, are family documents of the Iga and Iino clans. Some of the Iga clan in Kyoto became servants of the Muromachi shogunate, and the Bizen Iga clan continued to exist until 1578 (Tensho 6), when Hisataka became the lord of Kokura Castle in Bizen Province (present-day Okayama City).

[Tomohiro Watanabe]

"Iwaki City History Editorial Committee ed., Iwaki City History, Vol. 1 & 8 (1986, 1976)" ▽ "The Turning Point of the Kamakura Shogunate, by Nagai Susumu (2000, NHK Publishing)" ▽ "Iino Bunko ed., Definitive Iino Family Documents, Medieval Edition (2002)" ▽ "The Collected Works of Amino Yoshihiko, Vol. 6 (2007, Iwanami Shoten)"

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

中世東国の豪族、鎌倉幕府の吏僚。秀郷流(ひでさとりゅう)藤原氏。蔵人所(くろうどどころ)の下級官人であったが、藤原朝光(ともみつ)が1210年（承元4）3月19日に伊賀守に任ぜられ、以後伊賀氏を名乗るようになった。朝光は鎌倉幕府の成立より源頼朝に従い、幕府宿老として数々の戦功をあげた。1219年（承久1）朝光の子伊賀光季(みつすえ)は京都守護として上洛したが、1221年承久の乱で後鳥羽上皇方の軍に攻められ自刃。朝光の女(むすめ)は幕府執権北条義時の後室となったが、義時没後の1224年（元仁1）、兄の政所執事(まんどころしつじ)伊賀光宗と謀り自子政村を執権にし、女婿(じょせい)一条実雅(いちじょうさねまさ)を将軍に立てて幕府の実権を握ろうとしたと北条政子より嫌疑をかけられ、伊賀氏一族は幕政から一掃された。これは政子が世代交代による自らの権力の低下を防ごうとするための策略であったとみられる。伊賀氏一族は政子の死去によって赦免され、幕政に復帰して以後も代々幕府の吏僚として政務に重きをなし、1275年（建治1）光政が関東の評定衆から六波羅(ろくはら)評定衆に転じて以降、一族も主な活動の場を京都に移した。主な所領は陸奥(むつ)・常陸・武蔵・甲斐・信濃・若狭・備前・但馬(たじま)・筑前の各国に分布しており、邸宅は鎌倉と京都にあった。建武政権下では兼光が後醍醐天皇の寵臣として活躍し、また貞長は奥州小幕府二番引付(ひきつけ)となった。鎌倉末期の備前国守護光貞の猶子(ゆうし)盛光(もりみつ)は南北朝動乱期に陸奥国好島(よしま)荘に北遷して国人領主となり、足利方として活躍して東海道検断職(とうかいどうけんだんしき)に補任された。その子孫は荘内の郷名から飯野(いいの)氏を名乗るようになり、国指定重要文化財の「飯野家文書」は伊賀氏・飯野氏の家伝文書。在京の伊賀氏のなかには室町幕府の奉公衆となる者もあり、備前伊賀氏は1578年（天正6）の備前国虎倉城(こくらじょう)（現、岡山市）城主久隆まで存続する。

［渡辺智裕］

『いわき市史編さん委員会編『いわき市史』1・8（1986、1976）』▽『永井晋著『鎌倉幕府の転換点』（2000・日本放送出版協会）』▽『飯野文庫編『定本飯野家文書　中世篇』（2002）』▽『『網野善彦著作集』第6巻（2007・岩波書店）』

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