Reassessing Shōen: An International Conference
西田猛、兵庫県小野市立好古館、「考古学の成果からみた大部荘」
Nishida Takeshi, Kokokan, Ono city, Hyogo prefecture: “An Archaeological View of Ôbe Estate”
小野市は、兵庫県の南東部、播磨地区の北東（北播）に所在しています。市の中央を南北に流れる加古川の豊かな恵みにより古くから文化が開けてきたところです。地形的には加古川が造りだした広大な河岸段丘が広がっており、段丘上に形成された町と言えます。
今回のテーマである東大寺領大部荘は、河岸段丘が最も顕著である加古川左岸に位置しています。この左岸には、いくつもの段丘が形成されていますが、大きく分けて、低位段丘、中位段丘、高位段丘の三つに分けられます。標高でいえば、それぞれ30ｍ段丘面、50ｍ段丘面、70～100ｍ段丘面ということになります。では、これらの段丘面が、いつ開発されたかについて考えていきたいと思います。
まず、30ｍ段丘面ですが、ここはほ場整備という耕地整理が行われた時に調査が実施され、たくさんの集落遺跡が確認されています。その形成は、今から2000年前の弥生時代に始まります。その代表的なものとしては、高田古苗代、高田宮ノ後、敷地西、敷地北西、王子山ノ下西、王子辻ノ内、王子城ノ下遺跡などがあげられます。これらの集落は、次の古墳時代も続き、その時代の有力者の墓である古墳を50ｍ段丘面の先端部に築きます。その代表的なものが王塚古墳、敷地古墳を主墳とする大古墳群です。鏡や鉄製武具などが出土しており、大きな力をもっていたことがわかります。奈良時代になると50ｍ段丘面にお寺が建立されます。しかし、その寺は平安時代終わりころに無くなってしまったので、広渡廃寺跡と呼ばれています。現在、国の史跡で、史跡公園として整備されています。この寺は、その本尊を浄土寺薬師堂の本尊として移したとされています。
このように30ｍ段丘面は古くから集落が営まれて開発されましたが、50ｍ段丘面は古墳と寺院のみで、神聖な場所として残されていました。
50ｍ段丘面でこれ以外の遺跡がみつかるのは、平安時代の終わりころで、役所とみられる浄谷遺跡や土器を焼いた窯の南山遺跡などです。ちょうどこの時期は、東大寺がこれまで持っていた荘園と交換し、「大部荘」を手に入れた時期にあたっています。東大寺は、未開発の鹿野ケ原と呼ばれていた広大な50ｍ段丘面に魅力を感じたのではないでしょうか。しかし、開発は容易に進まなかったようです。その開発を推し進めたのが東大寺再建の勧進職となった重源上人です。荘園の四至牓示立て、その拠点として浄土寺を建立し、北池、南池などの水利を整え、開発を進めていきました。当地には、重源上人に関わる開発の伝承がいくつか残されています。たとえば、鹿野ケ原を一日で開発したとか、鍬で掘ったら水が湧いたというひと鍬掘り、鋤を洗ったので濁ったというにごり池、牛の鞍をかけたという鞍掛け松などがあります。このあたりのほ場整備に伴う調査では、水路、畔などが確認されており、その性格は集落というよりも生産遺跡となっています。
以上のように50ｍ段丘面の開発時期は、大部荘の成立以降ということになります。したがって現在50ｍ段丘面にある黒川、浄谷、中島、広渡の４町については、大部荘の成立と共に形成された集落と考えられます。氏子となる神社圏で見ても、30ｍ段丘面は熊野神社、50ｍ段丘面は浄土寺内の八幡神社とはっきり分かれています。
最後になりましたが、浄土寺には、宝持院と歓喜印の二つの塔頭寺院が残されていますが、元は11ケ寺以上あったとされています。ほ場整備に伴い浄土寺周辺の発掘調査を行うと、建物の柱を置く礎石などが見つかっています。建物はすでに失われていますが、その痕跡は、現在も土の中に残されています。
また、重源上人は、浄土寺だけでなく、大部荘の荘域外の長尾寺や来迎寺の建立にも深く関わっていました。長尾寺では鎌倉時代の瓦が多量に出土しています。これらは、その地が物資を運ぶ港であったり、用水を取り入れる水源であったりしたことがきっかけになったものだと推測しています。
以上、発掘調査の成果から大部荘の開発時期、また重源上人の大部荘での動きについて考えてみました。ぜひ、一度小野市にお越しいただき、浄土堂とその本尊である阿弥陀如来及び脇侍立像と、それを育くみ、大事に伝えてきた旧大部荘の現状をぜひご覧下さい。
**Note: The numbers in the text below indicate the illustrations that Mr. Nishida will show—see page 2 for a list.
Ono city is located in the southeastern portion of Hyôgo prefecture, in the northeastern portion of the Harima area (northern Harima). The abundant benefits of the Kako river, which flows through the present-day city, contributed to cultural development in the region from a very early age. A major topographic feature is the broad terrace along the bank, formed by the river. Ono city is located atop that terrace.
Tôdaiji’s holding Ôbe estate, one focus of this conference, was located on the most prominent terraced portion, along the east bank of the Kako river. (1) The land along the east bank rises in several terraces: broadly speaking, a lower, a middle, and an upper terrace—respectively 30, 50, and 70-100 meters in elevation. (2, 3, 4) I will discuss when these terraces were first opened to cultivation.
To begin, when investigations were conducted at the time that improvements were made in arable land, the remains of a number of hamlets were discovered, of a type that first appeared in the Yayoi period about 2000 years ago. (5) Representative sites include Takadafurunawashiro, Takadamiyanoushiro, Shikijinishi, Shikijihokusei, Ôjiyamanoshitanishi, Ôjitsujinouchi, and Ôjishironoshita. (6, 7, 8) These hamlets continued into the Tumulus period, and mounded tombs, the burial places for elites of the time, were built on the edge of the 50-meter terrace. Representative examples of such burial mounds are the Ôtsuka and Shikiji tombs. The mirrors and iron weapons excavated from these sites provide evidence that very powerful people were buried there. (9, 10) In the Nara period, a Buddhist temple was established on the 50-meter elevation, but by the end of the Heian period it had fallen into ruin, and the site is now known as the Kôdo temple remains. Now it has been designated as a national historic site, and has been established as a historical park. (11, 12) The main image worshipped at this temple was moved to Jôdoji’s Yakushi Hall at the northeastern edge of Ôbe estate.
Thus while villages were established and land was cultivated from ancient times on the 30-meter elevation, the 50-meter terrace was occupied only by temples and burial mounds, remaining sacred space.
Additional archaeological sites found on the 50-meter terrace date from the end of the Heian period: the Kiyotani site, thought to be a government office, and the Minamiyama site, location of a kiln where pottery was fired. (13) That was just the period when Tôdaiji established Ôbe estate there, in exchange for other holdings. Perhaps Tôdaiji monks were tempted by the broad terrace at the 50-meter elevation, the as-yet undeveloped land known as Kanogahara. However, developing this land did not proceed easily. Chôgen, the holy man who headed the campaign to rebuild Tôdaiji, (14) promoted this land reclamation effort through re-establishing boundary markers for the estate, building Jôdoji as his base of operations, and constructing irrigation facilities such as the North and South ponds. There are many traditions surrounding Chôgen’s activities there: for example, that he opened Kanogahara lands to cultivation in a single day; that when he dug in the ground with his hoe, water bubbled up; that Nigori (Muddy) pond was created from the mud that dripped from his hoe when he washed it; and that he hung his ox’s saddle on a pine tree, that came to be known as the Saddle-Hanging Pine. Investigations accompanying the improvement of arable in that area confirm that there were irrigation canals and rice-paddy ridges there. The remains seem to be those of agricultural production, not a dwelling site. (15)
The land reclamation on the 50-meter terrace took place after Ôbe estate was established. Thus 4 hamlets in the area—Kurokawa, Kiyotani, Nakajima, and Kôdo—are thought to have been founded at the same time as the estate. Residents of the two terraces were parishioners of two different shrines: those who lived on the lower terrace belonged to Kumano shrine, (16) and those on the terrace above, to Hachiman shrine (17) on the precincts of Jôdoji.
Originally there were eleven monks’ cottages within the Jôdoji precincts, and two of them—Hôjiin and Kankiin—remain. (18) The archaeological excavations that accompanied the improvement of arable land uncovered foundation stones for these buildings’ pillars. (19) The structures themselves have already disappeared, but their traces still remain in the earth.
Not only did Chôgen build Jôdoji, but he was also deeply involved in the construction of Nagaodera and Raigôji, beyond the boundaries of Ôbe estate. Many tiles dating to the Kamakura period have been found at the Nagaodera site. (20) These findings indicate that this area was a port for transport of materials, or a source of irrigation water.
(21) Using archaeological data, one can investigate the period when fields at Ôbe estate were reclaimed, as well as the activities of Chôgen at the estate. Please come to Ono city, and visit the location of Ôbe estate, to learn about Jôdodô and its famous Amida triad!
ILLUSTRATIONS
- Map of the terraced topography in the vicinity of Ôbe estate (30-meter, 50-meter, and 70-meter terraces)
- Photograph of the 30-meter terrace
- Photograph of the 50-meter terrace
- Photograph of the 70-100 meter terrace
- Map showing the distribution of archaeological sites before the construction of Jôdoji at the end of the 13th century
- Photograph of the dwelling site below Ôji castle.
- Photograph of archaeological site below Ôji castle (showing the condition of pottery excavated at the site)
- Photograph of the dwelling site below Ôji castle
- Photograph of Ôtsuka burial mound as it appears today
- Photograph of pottery excavated from Ôtsuka burial mound
- Photograph of remains of the Kondô (Golden Hall or Main Hall) at Kôdo temple ruins, as they appeared during excavation
- Photograph of the model of Kôdo temple in its original state
- Map showing the distribution of archaeological sites after the construction of Jôdoji
- Photograph of a portrait sculpture of Chôgen
- Photograph of the Kanogahara area today
- Photograph of Kumano shrine
- Photograph of Hachiman shrine at Jôdoji
- Map of the distribution of sub-temples within Jôdoji precincts
- Photograph of the excavation near Jôdoji (foundation stones of a building)
- Map of Ôbe estate terrain
- Photograph of Jôdodô at Jôdoji