Otomo clan

A powerful clan that flourished from the 5th to 9th centuries. A clan of gods said to be descendants of Amenooshihi-no-Mikoto, who served as a precursor to Ninigi-no-Mikoto, the grandson of the heavenly gods, they were first given the surname Muraji, and in 684 (the 13th year of Emperor Tenmu's reign) were given the surname Sukune. Together with the Mononobe clan, they were in charge of military affairs in the Yamato province, and were also active in politics. According to the Kojiki, Nihon shoki, Kogo shui and other sources, the son of Takamimusuhi no Mikoto (one theory says that he was the 5th generation descendant) was Amenooshihi no Mikoto, whose 3rd generation descendant was Michiomi no Mikoto, who led Emperor Jimmu's eastern expedition, and whose 7th generation descendant was Omuraji Muroya (all the following are real people) who lived during the five reigns of Emperors Yūryaku to Buretsu, and it is said that from his generation onwards it became his hereditary duty to guard the palace gates with an army of 3,000 strong men. Muroya's grandson Kanamura also served as a great minister during the five reigns of Emperors Buretsu to Kinmei, and executed the ministers Heguri no Matori and his son at Buretsu's command. After Buretsu's death, he welcomed Emperor Keitai from Echizen and played an important role in the Yamato court. However, he was forced to retire from politics after being criticized by Mononobe no Okoshi for his policy toward Korea, and the power of the Otomo clan finally began to decline. During the Taika period (645-650), Nagatoko became the Minister of the Right, and Makuta, Fukei, Miyuki, and others who sided with Prince Oama during the Jinshin War restored the family's fortunes, and in the 8th century, the family produced many high-ranking officials, including Yasumaro, Tabito, and Yakamochi, but it gradually fell into decline due to the advancement of the emerging aristocratic Fujiwara clan. In particular, the family rapidly declined when Yakamochi was stripped of all of the official positions he held during his lifetime as the mastermind behind the assassination of Fujiwara no Tanetsugu in 785 (Enryaku 4). In 823 (Kōnin 14), the family name was changed to Tomo to avoid the given name of Prince Otomo (Emperor Junna), but after the downfall of Dainagon Tomo Yoshio in the Otenmon Incident in 866 (Jogan 8), the Otomo family completely disappeared from the center of politics.

[Hiromichi Mayuzumi]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

5世紀から9世紀にかけて繁栄した有力氏族。天孫瓊瓊杵尊(ににぎのみこと)の先駆を務めた天押日命(あめのおしひのみこと)の後裔(こうえい)と伝える神別氏族で、初め連(むらじ)姓、684年（天武天皇13）宿禰(すくね)姓を賜う。物部(もののべ)氏とともに大和国家(やまとこっか)の軍事を担当し、政治面でも活躍した。記紀、『古語拾遺(こごしゅうい)』その他によれば、高皇産霊尊(たかみむすひのみこと)の子（一説に5世孫）が天押日命、その3世孫が神武(じんむ)東征の先導を勤めた道臣命(みちのおみのみこと)、さらにその7世孫が雄略(ゆうりゃく)～武烈(ぶれつ)5朝の大連(おおむらじ)室屋(むろや)（これ以降実在の人物）で、彼の代から靭負(ゆげい)3000を率いて宮門を警護することが世職となったという。室屋の孫金村(かなむら)も武烈～欽明(きんめい)の5朝に大連として歴仕し、武烈の意を受けて大臣(おおおみ)平群真鳥(へぐりのまとり)父子を誅殺(ちゅうさつ)し、武烈なきあとには越前(えちぜん)から継体(けいたい)を迎立して大和朝廷に重きをなした。しかし対朝鮮政策につき、物部尾輿(おこし)の非難攻撃を受けて政界を引退するのやむなきに至り、大伴氏の勢力はようやく衰退に向かった。大化（645～650）のころ長徳(ながとこ)が右大臣となり、さらに壬申(じんしん)の乱に大海人皇子(おおあまのおうじ)方についた馬来田(まくた)・吹負(ふけい)・御行(みゆき)らが家運を挽回(ばんかい)し、8世紀には安麻呂(やすまろ)、旅人(たびと)、家持(やかもち)ら多くの高官を出したが、新興貴族藤原氏の進出に押されてしだいに後退した。とくに785年（延暦4）藤原種継(たねつぐ)暗殺事件の首謀者として家持が生前の官位をことごとく剥奪(はくだつ)されるに及んで急速に衰えた。823年（弘仁14）大伴親王（淳和(じゅんな)天皇）の諱(いみな)を避けて伴(とも)氏と改めたが、866年（貞観8）応天門(おうてんもん)の変で大納言(だいなごん)伴善男(とものよしお)が失脚するに至って、大伴氏は政界中枢から完全にその姿を没した。

［黛　弘道］

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