The purpose of this paper is to clarify the characteristics of Kyōgoku-no-miya 京極宮 Prince Ayahito 文仁親王 as the head of a cadet branch of the imperial family by examining the process of his adoption into that family and the involvement of his father, the Retired Emperor Reigen 霊元上皇. Section one of this paper analyzes the process of adoption into the cadet branches of the imperial family led by princes during the Kan'ei to Enpō periods as the basis of this study, pointing out the following: While the Fushimi-no-miya 伏見宮家 family had maintained direct lineal succession since the Middle Ages, there were repeated cases where the heads of the family died early without leaving an heir in the Hachijō-no-miya 八条宮家 family (and their offspring Tokiwai-no-miya family 常盤井宮家, Kyōgoku-no-miya 京極宮家 family) and Arisugawa-no-miya family 有栖川宮家, and each time an imperial prince was adopted into a cadet branch of the imperial family. However, in these cases, the adoption of princes into cadet branches was not proactive and the imperial family did not proactively send a prince. Section two examines the process of Prince Ayahito's adoption into the Arisugawa-no-miya family during the Tenna to Jōkyō eras and the Retired Emperor Reigen's involvement, revealing the following: Retired Emperor Reigen expected Prince Ayahito to support Emperor Higashiyama not only in the succession to the throne, but also in decision-making within the Imperial Court. In order to fulfill this role, Prince Ayahito was adopted by Arisugawa-no-miya Prince Yukihito 幸仁親王 after Retired Emperor Reigen rejected requests from the monzeki temples for the prince to serve as a successor. Section three analyzes the process from the dissolution of Prince Ayahito's adoption by the Arisugawa-no-miya family during the Genroku era until Prince Ayahito's independence as head of the Kyōgoku-no-miya family, revealing the following: When a prince was born to Prince Yukihito, the possibility arose that Prince Ayahito's adoption would be dissolved and he would be adopted into the Tokiwai-no-miya family, which had no head of the family. However, Retired Emperor Reigen perceived the successive early deaths of the Tokiwai-no-miya family heads as an ominous sign and refused to allow the adoption of Prince Ayahito. The ominous sign was eliminated by changing the Tokiwai-no-miya family name to Kyōgoku-no-miya and relocating its residence. Prince Ayahito then inherited leadership of the Kyōgoku-no-miya family. The above analysis reveals that Prince Ayahito was unlike the many contemporaneous heads of cadet branches of the imperial family in that he was intentionally and deliberately appointed as head of a cadet branch of the imperial family by Retired Emperor Reigen. Furthermore, the treatment of imperial princes, the selection process of the crown prince, as well as how lay princes other than the crown prince were secured, could be important issues in clarifying the actual state of early modern court management.
Akihito YAMAMURA (Sun,) studied this question.