神泉苑の誕生

Abstract

本稿では、まず、故中山修一が長岡京発掘の基準史料とした延暦十四年正月二十九日官符を再読した。そして、官符によって勅旨所・近衛府に下賜された旧長岡京左京三条一坊八・九・十・十五・十六町には、長岡京期、京内離宮「南園」が位置した、と推測した。その上で、「南園」は、長岡京後期、宮城南面地区が全面的に改造された際、早良東宮跡地に造成された可能性が高いことを指摘した。長岡京末期の「南園」における三月三日節会は禊祓儀礼としての性格を強く有したが、それは、年中行事の儀場を固定化する契機でもあった。平安遷都後、桓武は、豊楽院など他の饗宴施設と平行して、長岡京「南園」と同じ左京三条一坊に神泉苑を造営した。禁苑としての偉容を具備した神泉苑には、平城・嵯峨期にさまざまな詩宴が集約され、「文章経国」の政治文化を象徴する舞台として機能したのである。

This study focuses on the creation of the Shinsen-en 神泉苑, a royal garden in the Heian-kyo, and also attempts to recreate the changes it underwent as a spatial component of the capital in the early Heian period. In 1953 the late Nakayama Shuichi 中山修一 discovered the site of the Konoefu 近衛府 hasuike (the lotus pond of the headquarters of the Inner Palace Guards) that is mentioned in a Dajokan kanpu (an order of the Great Council of State) dated the 29th day of the first month of Enryaku 14 (795). Using this as a clue, Nakayama set out to excavate Nagaoka-kyo, which had been called the capital of dreams. This study begins with a rereading of these materials. It is hypothesized that (1) a detached palace, rikyu, called the Nan-en 南園 was established over the 8th, 9th, 10th, 15th, and 16th block, cho, at Sanjo-Ichibo in the western ward of the city while the capital was located in Nagaoka, and that (2) the land was awarded to the Chokushisho 勅旨所 and the Konoefu after the transfer of the capital to Heian-kyo. This study then moves to a critical appraisal of the archaeological studies of Yamanaka Akira 山中章 on the Nagaoka palace and surroundings of the capital. The earlier hypothesis is thereby supported, and it is pointed out that it is highly probable that the when the southern portion of the capital was rebuilt in the later part of the Nagaoka-kyo period, the Nan-en was constructed on the site of the palace of crown prince Sawara, who had been deposed in Enryaku 4 (785). In the final years of the Nagaoka-kyo era, the celebration of Third day of the Third month Celebration, which included a banquet that involved the composition of poetry along a meandering brook in the garden, kyokusuinoen 曲水宴, was held for three consecutive years at the Nan-en. Observations of the celebration in Enryaku 11 and 12 had the clear character of a purification, misogi, rite due to the successive indisposition and illness of the emperor. However, with each new observation of an annual event on the court calendar, the locations for the ceremonies became fixed. Shortly after the transfer of the capital to Heian-kyo, Emperor Kanmu began construction of the Buraku-in 豊楽院 as a ceremonial site for national rituals as well as the Shinsen-en. The location of the Shinsen-en was patterned on the site of the Nan-en in Nagaoka-kyo, being situated at Sanjo-Ichibo in the western half of the new capital, but it was expanded to cover eight cho. The fact that the placement of the Shinsen-en within the spatial layout of Heian-kyo was designed to correspond to the southern boundary of the palace grounds (at Nijo Oji) was of great significance. In view of the cultural character of the reign of Kanmu and the legend of the view of the southern pond of the palace in Baekje capital of Buyo, these factors may have influenced the location of the Shinsen-en. Shinsen-en first appears in the historical record in Enryaku 19 (800), but it was used only irregularly as a location for banqueting during the reign of Kanmu. Emperor Kanmu conceived of preparing separate sites for each of the major ceremonies in the capital, but such a plan could only be put into practice after Kanmu's death. The preparation of the Shinsen-en as a royal garden was completed by the reigns of Heijo and Saga and served as the location of the ceremonies for the annual observances such as the Third of the Third month, the Seventh of the Seventh month, the Ninth of the Ninth and the Flower Banquet. The element common to all of these ceremonies was the inclusion of a banquet featuring the composition of Chinese verse. The early Heian period was characterized by the concept of bunsho keikoku 文章経国, the belief that literature had the power to assist in the operation and rule of the state, and the Shinsen-en served as the stage on which political culture of the period was played out. Emperor Kanmu sought an ideal capital that could represent the orthodoxy of his rule, and the Shinsen-en was the space created in the Heian-kyo to embody his will.