<論説>平安期平城京域の空間利用とその支配

Abstract

廃都後の平城京域は貞観六年の「都城道路変為田畝」という記事により、大部分が早期に水田化したとされ、興福寺膝下に成立した中世都市奈良のみが存続したと概説される。しかしながら、それを裏付けるべき、水田化の具体的な変化の過程やその空間的差異、推進主体ないし背景について、十全に明らかにされているとは言い難い。そこで、本稿では、平安期の平城京域を対象として、(1)土地利用変化のプロセスとその空間附差異の解明、(2)それに対応した領域編成形態の態様の抽出、(3)空間支配の歴史的展開への位置付け、という景観や領域形態という空間的次元を重視した三段階からなる検討によって、実証的な議論を行うことを試みた。

This paper analyzes the transformation of territorial occupation and administration the former Heijyo capital (平城京) area in early medieval Japan. Heijyo kyo was the capital city of Japan in the eighth century. It has been considered that most of its urban area was desolated immediately into paddy field after removal of the capital. Within it only Nara, the town attached to the Kouhukuji temple survived and became a mediaeval town. The author investigates the changing process from three aspects: the transformation of land utilization, the territorial occupation and administration. Concerning the land utilization, four features can be clarified as follows: (1) Paddy fields became dominant in the eleventh century. The land utilization is found to have changed gradually and underwent two stages: From the residence to cultivated land, and then further to paddy field. (2) The process of the change of the land into paddy field was characterized by geographical difference. Urban features might have existed in the places such as the ancient market squares and temple grounds besides Nara, the medieval town. (3) The large temples and the established centers of marketing system could support urban land use. (4) The spatial structures of the land utilization shown by contracts fundamentally correspond with the historical sites of buildings and roads emerged from recent archaeological investigation. It can be concluded that there was a noticeable transformation in the territorial occupation and administration of Heijyo capital in the mid ninth century. After the removal of the capital, the city area of Heijyo was not administrated by the universal system, as the land rights originated in the metropolitan period were well prescribed in the first half of the ninth century. It was actually formed by the territorial administrative system inherited from the metropolitan period and the manors of large temples and local government. From the eleventh century onwards, the Kouhukuji temple reorganized the territorial administration, and gradually placed itself at the top of the administration hierarchy. It is considered that the big fire of Nara caused by war disasters in the twelfth century accelerated this tendency.