長門国府・国分寺を中心とした軒瓦の様相 <原著論文>

瓦は,古代の遺跡から出土する考古資料のなかで最も普遍的な遺物であり,同時に多くの歴史事象を引き出せる遺物でもある。氏寺では,地方においても早くから主要な堂塔に瓦が葺かれたが,一方で奈良時代に至っても国々の国衙が直接に維持管理する施設への導入と展開は,その国がおかれていた状況によって大きく異なると考えられる。

筆者は,これまで古代安芸国のあり方を論じてきたが,これとの比較のため,同じ山陽道に属する古代長門国の国庁・駅家・国分寺などと推定される遺跡から出土した軒瓦を中心に,瓦当文様とともに製作技法の検討を行った。

その結果,瓦当文様は時間の経過とともに型式変化が生じるが,製作技法は一貫して当初のものが続いており,しかも国庁など地方官衙での使用が先行し,その後,国分寺に供給されているのである。このため,官営工房(国衙工房)が国分寺創建以前から設けられていた安芸国と同様に,長門国においてもこうした工房に属する造瓦工人らが瓦生産に携わっていたことが考えられた。

また併せて周防国府出土の軒瓦について検討したところ,瓦当文様と製作技法に長門国庁などとの共通点が多く,当初はこの国衙工房から一時的に造瓦工人を派遣した可能性が推定された。

Roof tiles are considered to be the most universal relics among archeological data unearthed at ancient ruins, and they also offer much historical event information. For Ujidera, the clan's temple, tiles were introduced and used for its cloistered units from early on in the region. However, for the facilities directly maintained by the provincial government office, it is considered that the timing of the introduction and development of the tiles varied widely based on the state of its government even in the Nara period.

I have been discussing the state of the ancient Aki-koku up to this point; however, for comparison we analyzed eaves tile end piece designs and fabrication techniques of the eaves tiles unearthed from relics identified as being from the ancient Nagato-koku provincial office, posting stations, and Kokubunji provincial temple, which all belong to the same San'yo-dō.

As a result, different type of eaves tile end piece designs have been found over different periods of time; however, similar fabrication techniques are consistently used from the beginning. In addition, eaves tile end pieces were introduced to the provincial office earlier and then to the Kokubunji provincial temple. For this reason, it is presumed that in Nagatokoku, as it is for the Aki-koku, tile makers who belonged to the provincial government office workshops were producing tiles.

I also studied the eaves tiles unearthed in the Suou-koku, and it is estimated that tile makers were dispatched from the provincial government office workshops of Nagato to this province for a certain period of time as many similarities have been found in the eaves tile end piece design and its fabrication technique between these two regions.