古代宮殿建築における前殿と朝堂 : その 3 平城宮 (2)

Abstract

On the previous paper and this paper, we have investigated Daigoku-den, Chodo and Daian-den, Nan-en or Nan-in, of Heijo Imperial Palace, and considered the relations between them. The main results obtained from this study are as follows : 1) The original Daigoku-den and Chodo of Heijo Imperial Palace were built to the north of the Suzakumon (the main gate of the Imperial Palace). They are supposed to have been used as the Daigoku-den and the Chodo, until the transfer of the capital to Kuni-kyo (740 A. D.). Daigoku-den, the supreme hall in Heijo-kyu, was used for the national ceremonies like the Gensho-Choga (New Year's audiences) and the enthronement. Chodo was used as halls for official ceremonies and banquets, and also for administering State affairs, alike Chodo of Fujiwara-kyu. 2) It is supposed that Daian-den was built to the east of the original Daigoku-den, and the southern part of the Daian-den was called the Nan-en (the Imperial garden) in the reign of the Emperor Shomu. Daian-den of Heijo-kyu is considered to have followed that of Fujiwara-kyu and Aska-kiyomihara-kyu which were the supreme hall of Naicho, or the residential part of the Imperial Palace. Nan-en seems to have been used for private banquets. 3) Daigoku-den of Heijo Imperial Palace was removed and reconstructed in Kuni Imperial Palace in 740. Although the Emperor Shomu transferred the capital again to Heijo-kyo in 745, Daigoku-den was not reconstructed in the place of the former Daigoku-den in Heijo Imperial Palace. After the capital was transferred to Heijo-kyo, the Daian-den is supposed to have been used as Daigoku-den. 4) Daigokuden-nanin or Nan-in described in the chapter of the Empress Koken of Shokunihongi is considered to have been originally the Nan-en in the reign of the Emperor Shomu. In the reign of the Empress Koken, the Chodo which was located to the north of the Suzakumon was used as Chodo, or the Halls of State. 5) It can be assumed that, as a result of the repairs of Heijo-kyu from 760 to 762, the Daian-den was remodeled into Daigoku-den and the Nan-in into Chodo. Therefore the precinct of the original Chodo seems to have been mainly used for private banquets.