The origins and transformation of tomb name listings in ancient Japan

The Engishiki 延喜式, specifications clarifying the Ritsuryo legal codes written during the Engi era (901‐923 CE), contain an ordered listing of the names of 120 tombs (ryobo 陵墓) of the emperors, their families and entourages. Regarding a similar listing in the Ritsuryo specifications for the earlier Konin era (810‐824), a debate has arisen among scholars as to its origin and order of listing. In the present article, the author enters that debate by extracting the names contained in the Engishiki listing that also appeared in the Konin listing, examining their order, for the purpose of discussing such characteristics as their origin and why they were compiles. To begin with, in the original listing, the order of the tomb names begins with the tombs of the emperors (ryo 陵) followed by the tombs (bo 墓) of their biological mothers and grandmothers, then fathers granted the title of emperor (tenno 天皇) posthumously and princes and princesses, following precedent, as does the tombs of aristocrats who were thought possible heirs to the throne. This kind of listing is observed during the reign of Emperor Kinmei (r.539‐552), the first known regime to include the tombs of matrilines and children in the listing. This original listing was first compiled as a ledger for managing the tombs under the protection of the state, with the aim of assuring the legitimization of imperial succession.<br> Upon the promulgation of the Ritsuryo Codes of the Taiho era (701), the tomb name listing was divided into two parts: one for imperial ryo and one for all other bo. The order of the latter part conformed to the precedent observed since the reign of Kinmei: three matrilineal generations, persons honored with the title of emperor, and other persons following the traditional precedent. In the post-Taiho Code listings, a new type of ledger was introduced for the purpose of managing the tombs designated for first fruits (nosaki 荷前) offerings. Then from the mid-8th century on, as the result of enhanced regard for ties of kinship, the three dowagers and imperial fathers were added to the listing; and during the reign of Emperor Kammu (r.737‐806), fathers and mothers of imperial consorts were added. Such changes in the ryobo system effected by the Ritsuryo Codes were incorporated into the way in which the Koninshiki listed the names of the related tombs, which was the followed by the Engishiki.<br> The author concludes that there is the distinct possibility of the Engishiki listing being a remnant of the conditions surrounding the political process, in general, and the question of imperial succession, in particular, which had unfolded since the beginning of the 6th century.