These documents show how the Record of Kaigen-no-Sadame by Lord Tsunemitsu was created based on an accumulation of daily records including the History of Lord Tsunemitsu and the Journal of Lord Tsunemitsu (Minkeiki). Furthermore, the records written by Tsunemitsu vividly express the passion with which he engaged in recordkeeping. It can be said that the accumulated efforts of civil servants like Tsunemitsu were one of the major elements in forming the significance of era names. At any rate, although ancient records have been transcribed into typeset, preparing for the exhibition taught me that it is sometimes necessary to view the original materials in order to understand the actions and feelings of historical figures.
The French historian Jacques Le Goff explained the significance of historical periods as follows: “The act of dividing history into periods is complex. Although this act must be subjective, at the same time, an effort must be made to produce results which will be accepted by as many people as possible” (from a translation of “Must We Divide History Into Periods?” by Jun Suganuma.) Le Goff’s observation can also be applied to era names, which are a type of historical division. Furthermore, I entirely agree with Le Goff’s opinion that “this is an extremely fascinating historical research theme.” For example, the deliberation which occurred at the Kaigen-no-Sadame (this deliberation is called nanchin in Japanese) provides a glimpse of human drama that includes cooperation and interference among court nobles. Tracing the deliberation back to its source makes it possible to inquire into changes in how Chinese classics are accepted in Japan, which is a subject of endless interest. Although some aspects of era names are not directly related to my area of expertise, I will continue to enjoy this theme until Japan changes into its next era name.