Dazaifu

In ancient times, it was an office that administered the entire Saikaido (Kyushu) region and was given the authority to defend against foreign invasions and to act as a focal point for diplomacy. The origin of such an office can be traced back to the 3rd century, when Himiko appointed Ichidaisotsu in Ito Province to supervise negotiations with the continent, but it should also be noted that in the first half of the 6th century, after the pacification of Tsukushi no Kimi Iwai, Emperor Senka established a government office in Nanotsu and ordered his ministers to transport military supplies and ensure that the army was well prepared. However, the name "Tsukushi no Taisai" was first seen in 609 (the 17th year of the reign of Empress Suiko). During the reign of Empress Suiko, the Silla issue arose frequently and the dispatch of Japanese envoys to the Sui Dynasty was also an important diplomatic period, so the responsibilities of the "Tsukushi Dazai" were heavy. The Battle of Baekgang (663) marked a major turning point for the Dazaifu. The Japanese army, which had gone to the rescue of Baekje, was defeated in a naval battle by the combined forces of Tang and Silla. The Japanese army withdrew with the remaining Baekje retainers, but was soon exposed to the threat of an invasion by Tang and Silla. Emperor Tenji stationed defenders and beacons along the coastline of Tsushima, Iki, and Tsukushi. At the same time, he retreated the Dazaifu to the line from Nanotsu to Mizuki for defense. An earthwork was built to connect the narrow mountainous area in front of Dazaifu. This earthwork (large embankment) is a long embankment that is 1.2 kilometers long and 13 meters high. Wooden gutters were buried in the earthwork, and water was drawn into them when necessary and poured into the moat pond in front of the earthwork. For this reason, it was called a water castle. Furthermore, he had the surviving retainers of Baekje build Ono Castle on the mountain behind Tofuro. A circumference of about 6.5 kilometers of earthworks and stone ramparts were built around the ridge of the bowl-shaped mountain, and the so-called "100-ken stone wall" was built in the valley to the north. Barracks, weapons storehouses, food storehouses and other buildings were constructed at key points, and it is said that over 60 of these have been confirmed to exist to date. Other castles built in succession included Hizen's Kabuki Castle, Tsushima's Kaneda Castle, Sanuki's Yashima Castle, and Yamato's Takayasu Castle, strengthening the strategic military links to the capital. However, Tang and Silla fought over the unification of Korea, and attacks on Japan were avoided for the time being. The Dazaifu was then given the responsibility of governing the Saikaido and foreign affairs, and was organized as a special administrative agency. Its chief was often a minister-level figure or a member of the imperial family, and the Dazaifu was read in the Wamyōshō as "Oomikotomochi no Tsukasa" (the governor of the Imperial Court), and was also called "To no Mikado" (the distant imperial court), and was given great authority.

Under the Ryo system, the official ranks were as follows: Kamutsukasa, Sochi, Daini, Shoni, Daigen, Shokan, Daisakan, Shoten, Daijudge, Shojudge, Daireishi, Shoryoshi, Carpenter, Shocarpenter, Doctor, Onmyouji, Doctor, Sanshi, Sakimorinokami, Sakimorinosuke, Ryouushi, Shusen, Shuchu, Shisho. The chief deity was the Jingikan (Shinto priest) of the central government, and the Dazai no Sochi (Grand Chief Minister) and below were the Daijokan (Grand Councillors). The Dazaifu governed the states of the Saikaido region, and so the so-called Kyukoku Sanshima (the nine provinces of Chikuzen, Chikugo, Buzen, Bungo, Hizen, Higo, Hyuga, Osumi, and Satsuma, and the three islands of Iki, Tsushima, and Tane) were under its control.

For this reason, controlling Dazaifu gave them a political advantage. During the Jinshin Rebellion (672), the Omi faction tried to win it over to their side, and this area was also the site of the Fujiwara Hirotsugu Rebellion (740) and Fujiwara Sumitomo Rebellion (941). Dazaifu was burned down each time, but the ruins were leveled and rebuilt. Even today, burnt soil from the mid-Heian period can be found about 60 centimeters below the topsoil, and remains from the Nara period have been found even deeper below that.

Of course, Dazaifu was not only the political and military center, but also a cultural base on the Saikaido. In Buddhism, Kanzeonji Temple, where the Kaidan (ordination platform) was established, and in academics, Gakugyoin (Gakugyoin) dominated the area. In addition to Hakase (doctors), there were also Onhakase (professional doctors), who taught national students and were bestowed with books such as the Records of the Grand Historian, Book of Han, Book of the Later Han, Records of the Three Kingdoms, and Book of Jin.

Later, as the Ritsuryo system relaxed, the structure and control of the Dazaifu also declined, and in the Heian period, most high-ranking officials were not appointed, and real power was transferred to the Shoni. Furthermore, when the Kamakura Shogunate established the Chinzei Bugyo (magistrate of the Chinzei region), the Dazaifu became nothing more than a name.

[Tatsuo Inoue]

"A Study of the Dazaifu Capital City" by Takeshi Kagamiyama (1977, Kazama Shobo) " "Dazaifu" by Yasuhiko Kurazumi (1979, Kyoikusha)

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

古代において西海道(さいかいどう)（九州）全域を行政下に置き、外寇(がいこう)の防衛と外交の衝にあたる権限を与えられた官庁である。それに類する役所の起源については3世紀、卑弥呼(ひみこ)が伊都(いと)国に一大率(いちだいそつ)を置いて大陸交渉の監察にあたらせたこともあげられるが、6世紀の前半、筑紫君磐井(つくしのきみいわい)の平定後、宣化(せんか)天皇は那ノ津(なのつ)に官家(みやけ)を設け、諸臣に命じて軍粮(ぐんろう)を運輸せしめて非常に備えさせたことをあげるべきであろう。だが、実際に「筑紫大宰(つくしのたいさい)」の名の初見は、609年（推古天皇17）である。推古(すいこ)朝は、新羅(しらぎ)問題がしばしばおこり、また遣隋使(けんずいし)派遣も始められるという外交上重要な時期だけに「筑紫大宰」の任も重かったようである。大宰府の大きな転換期となったのは、白村江(はくそんこう)の戦い（663）である。唐・新羅の連合軍の前に、百済(くだら)の救援に赴いた日本軍は海戦で大敗した。百済の遺臣らとともに引き揚げてきたが、ただちに唐・新羅の侵攻の脅威にさらされることになった。天智(てんじ)天皇は対馬(つしま)・壱岐(いき)、あるいは筑紫の海岸線に沿って防人(さきもり)を配し、烽(とぶひ)を置いた。同時に防衛を考えて、那ノ津から水城(みずき)の線まで大宰府を後退させた。大宰府の前面の、山地の狭く迫る所を土塁で結んだ。この土塁（大堤）は全長1.2キロメートル、高さ13メートルに及ぶ長大な堤である。土塁には木樋(もくひ)を埋め、事あるときはこれに水を引き、土塁の前面の堀池に水を流し込んだ。それゆえこれを水城と称した。さらに、百済の遺臣たちをして、都府楼(とふろう)の後方の山に大野城をつくらせた。すり鉢状の山の尾根伝いに、1周約6.5キロメートルの土塁や石塁を巡らし、北側の谷は、いわゆる「百間石垣」を築いている。その要所要所には兵舎や武器倉庫、食糧倉庫などの建物がつくられたが、現在60余棟が確認されているという。そのほか、肥前(ひぜん)の椽(き)城、対馬の金田(かねだ)城、讃岐(さぬき)の屋島(やしま)城および大和(やまと)の高安(たかやす)城などが相次いでつくられ、都までの軍事上の要衝地が固められた。しかし、朝鮮の統一をめぐって、唐と新羅が争うこととなり、いちおう日本への攻撃は回避されることとなった。その後、大宰府は、西海道の統轄と外交の任を与えられ、特別行政府としての体制を整えることになったが、その長官には大臣クラスの人物や皇族が選ばれることも多く、大宰府は、『和名抄(わみょうしょう)』で、「おほみこともちのつかさ」と訓(よ)まれ、また「遠(とお)の朝廷(みかど)」ともよばれ大きな権限を与えられることになった。

　令(りょう)制では、「主神(かむつかさ)、帥(そち)、大弐(だいに)、少弐(しょうに)、大監(だいげん)、少監、大典(だいさかん)、少典、大判事(だいはんじ)、少判事、大令史(だいれいし)、少令史、大工(だいく)、少工、博士(はかせ)、陰陽師(おんみょうじ)、医師(くすし)、算師(さんし)、防人正(さきもりのかみ)、防人佑(さきもりのすけ)、令史(りょうし)、主船(しゅせん)、主厨(しゅちゅう)、史生(ししょう)」といった官人構成をなしていた。主神は中央官庁の神祇(じんぎ)官、大宰帥(だざいのそち)以下が太政(だいじょう)官に相当する。大宰府は西海道諸国を統治下に置いたから、いわゆる九国三島（筑前(ちくぜん)、筑後(ちくご)、豊前(ぶぜん)、豊後(ぶんご)、肥前(ひぜん)、肥後、日向(ひゅうが)、大隅(おおすみ)、薩摩(さつま)の九国と壱岐、対馬、多褹(たね)の三島）が行政下にあった。

　それだけに大宰府を抑えることは政治的にも優位にたつことができた。壬申(じんしん)の乱（672）のときも、近江(おうみ)方はこれを味方に引き入れようと努めたし、藤原広嗣(ひろつぐ)の乱（740）や藤原純友(すみとも)の乱（941）にも、直接この地が争乱の舞台となった。そのたびごとに大宰府は焼失したが、焼け跡を整地した上にまた再建され直された。現在でも、表土の60センチメートルばかり下には平安中期の焼土が堆積(たいせき)し、そのさらに下には奈良朝期の遺構なども検出されている。

　もちろん、大宰府は以上のように政治や軍事の中心であったばかりでなく、文化的にも西海道の拠点であった。仏教では戒壇(かいだん)が設けられた観世音寺(かんぜおんじ)が、学問では学業院(がくぎょういん)が、その地位を占めていた。博士(はかせ)のほか音博士(おんはかせ)もおり、五経とともに『史記』『漢書(かんじょ)』『後漢書(ごかんじょ)』『三国志』『晋書(しんじょ)』など賜下されて、国学生(くにがくしょう)たちを教授していた。

　その後、律令制の弛緩(しかん)に伴い大宰府の機構・統制も衰退し、平安時代に入ると上級官人はほとんど赴任せず、実権は少弐の手に移った。さらに鎌倉幕府が鎮西奉行(ちんぜいぶぎょう)を置くに及び、大宰府は有名無実となった。

［井上辰雄］

『鏡山猛著『大宰府都城の研究』（1977・風間書房）』▽『倉住靖彦著『大宰府』（1979・教育社）』

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