<論説>平安時代中後期の里内裏空間

Abstract

里内裏は、平安宮内裏焼亡を契機として平安中期に出現した京内(里) の天皇在所であるが、以降、次第に平安宮内裏に取って代わっていく。里内裏の空間構造に関して、その邸宅の周囲三町四方に、大内裏に擬せられる「陣中」という空間が存在することが、先行研究で指摘された。それは里内裏の性格や意義を考察する上で重要な指摘であった。しかし、その空間の成立や変化などについてはまだ検討の余地があると考え、本稿ではその再検討を行った。得られた結論は、里内裏には、平安宮内裏の「陣中」から連なる衛門陣を境界とする邸宅内陣中と、邸宅の外に広がる三町四方の邸宅外陣中の、二つの「陣中」が存在し、邸宅外陣中の確立は一一世紀末であるというものであった。そして、その確立は里内裏の一つの変質点であり、白河朝からの、里内裏本宮化という皇居制度変革の流れの中に位置付けられると考えた。

The sato-dairi first appeared during the mid-Heian period when the Heiankyu- dairi (originally the residence of the emperor) burned down and it became a temporary imperial residence in Heiankyo (sato 里). Thereafter, the sato-dairi gradually came to replace the Heiankyu-dairi. Previous studies have pointed out that in regard to the spatial-structure of the sato-dairi there existed a residential area called the jinchu (陣中) that extended out for a distance of three cho (町) in each direction, patterned on the Heiankyu. These findings are an important factor in considering the character and significance of the sato-dairi. However, I believe there has been insufficient consideration given to the formation and changes in the jinchu, and thus I have carried out a re-examination of the jinchu in this study and arrived at the following conclusions. I believe there were two jinchu in the sato- dairi. One jinchu assumed the character of the jinchu in the Heiankyu-dairi, with gate of the residence serving as its border. The second jinchu extended outward 3-cho every direction from the residence. The latter was formed at an end in the eleventh century. I have concluded that its formation was a turning point in the development of the character of the sato-dairi, and it can be judged a part of a series of changes in the imperial palace system instituted from the time of the Emperor Shirakawa.