<論説>陵号考 --山陵制度転回の一齣--

Abstract

本稿は山陵（王陵）に関する研究の素材として、文献史料としての「陵号」に注目する。古代日本が大陸から取り入れた陵号による天皇陵呼称は中世にも引き継がれた。しかし、中世公家社会においては陵号の誤認も広がっている。本稿では公家社会の政務やそこで作成された文書を注意深く観察することにより、陵号とそれに対する貴族の認識を検討した。その結果、摂関期においてふたつの天皇陵が同一の呼称を陵号とし、あるいは実態の変化を伴わずただ陵号だけが変更される複雑な事態が存在したことが分かった。また貴族の山陵に対する関心が、今上天皇との関係性（誰の山陵か）に集中した結果、遺体の所在地に因んだ古代以来の陵号がミスマッチな存在になってしまったことも混乱の背景に見出した。こうした使い勝手の悪さにもかかわらず、古代に固執するかのように、中世公家社会は陵号を用いていたのである。

The study of pre-modern Japanese imperial tombs has been concentrated on the ancient period for which there exists a sufficient body of primary sources. But, for the medieval period, studies have been speculative due the paucity of historical sources. As a result, little interest has been paid to imperial tombs from the medieval period. However, due to advances in the research in recent years, it has become clear that this view is incorrect. On one hand, this does not however indicate that the historical facts that previous scholarship relied upon have disappeared. In other words, Kamakura-period aristocrats frequently erred in identifying the names of the tombs (ryōgō 陵号) and the emperors were called by the names of those tombs in which they were interred. This is the case, even though recent research has made clear that imperial tombs were important monuments for the medieval court, just as they had been in ancient times. Why then did this occur? Referring to the tombs of Japanese emperors by a tomb name is modeled on the continental system of tomb names, linghao 陵号, used for Chinese emperors. Ancient Japan, which looked to the Chinese model in state formation, placed all the tombs of previous emperors under the jurisdiction of the state, and conferred a name on each based on the location of the tomb. Paired with the name of the emperor interred there, these were recorded in a list of imperial tombs. After the 10th century, the list ceased to be compiled, but the custom of calling the tomb of the emperor by a tomb name persisted. However, unlike the ancient state that emphasized the tombs of all preceding emperors as important monuments, in the medieval period, tombs of emperors who were especially significant as closely related kin of the reigning emperor were given special significance. Envoys were often dispatched by the court to these special imperial tombs, and the appointment of these envoys and their written records used the traditional tomb names, just as in ancient times. The dispatch of the envoy, while taking precedent into account to a certain extent, was determined by consideration of his relationship to the reigning emperor. That is to say, the identity of emperor who was to receive an envoy was an important criterion in the selection. However, when the aristocrats examined the precedents, they found the traditional tomb names from ancient times were recorded in the documents that recorded the decisions on the envoys. Because the tomb name was based on the location of the tomb, that alone would not make clear which emperor was interred at the site. The tomb names that revealed the location of imperial tombs from ancient times turned out to be an inconvenient system for medieval aristocrats who emphasized dispatching envoys to the proper emperor. Furthermore, as the method of burying the remains of the emperors changed greatly in the 11th century, confusion sprang up in the system of tomb names. Unlike the ancient state which had in principle assigned a different name to each tomb to help manage the imperial tombs, from the 11th century onward, names that had previously been used for other emperors were assigned to imperial tombs, which became a source of greater confusion. In other words, the errors caused by medieval aristocrats mentioned above were not due to any lack of interest on their part in the imperial tombs; the cause was the system of tomb names had become anachronistic. In this fashion during the medieval period, the system of tomb names that had been preserved since ancient times clearly became extremely inconvenient. Nevertheless, medieval aristocrats continued to use this cumbersome system. This was due to the fact that during the medieval period tomb names became an important medium for expressing their own aristocratic traditions.