Kaigen Nanchin - Kaigen Nanchin

...Although it has been said that the change of era name due to auspicious events, disasters, or revolutions was intended to bring good fortune and expel disasters through the magical power of the era name, it should be understood as a kind of political technique to materialize and establish the state's belief or assertion that era names have such magical powers. Regarding the procedure for changing the era name, according to ritual books and event records compiled after the 10th century, the Emperor ordered people skilled in writing, such as Sugawara, Oe, and Fujiwara, to select favorable characters from Chinese classics (this is called era name review), and then the Emperor would decide on the name after the nobles had deliberated on the original proposal (this is called era name review). However, in the Kamakura period, after the Jōkyū War in 1224, the era name was changed to Gennin, but after protests from the shogunate it was quickly changed back to Karoku, and again in 1308, at the shogunate's request, the era name was changed to Enkei. In the Muromachi period, the era name was changed to Shitoku in 1384 at the initiative of Shogun Ashikaga Yoshimitsu, but Emperor Shokō, who ascended to the throne in 1412 (Oei 19), was unable to change the era name for his entire reign due to the shogunate's wishes. As a result, the shogunate's interference in era name changes gradually increased, and the system of the emperor formally deciding on the new era name after the shogun's approval became fixed under the Muromachi shogunate, and this system was continued in the Edo shogunate as well.

*Some of the terminology explanations that refer to "Kaigen Nanchin" are listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…以上，祥瑞，災異，革命を理由とする改元は，年号のもつ呪力によって招福攘災を期するものとも説かれるけれども，むしろ年号にそのような呪力ありとする国家側の信仰もしくは主張を実体化し定着させようとする一種の政治技術と解すべきであろう。　改元手続については，10世紀以降に成った儀式書や行事記録によると，菅原，大江，藤原等の文章道の人々に命じて漢籍から好字を選ばせ(これを年号勘申（かんじん）という)，この原案について公卿が審議(これを改元難陳（なんちん）という)したうえで，天皇が決定する定めであった。しかし鎌倉時代に入り承久の乱後の1224年に元仁と改元したのに対して幕府の抗議があってたちまち再度嘉禄と改元し，また1308年同じく幕府の申入れによって延慶と改元，室町時代には1384年の至徳改元が将軍足利義満の発議で行われ，1412年(応永19)即位した称光天皇が幕府の意向で一代の間ついに改元できなかったなど，改元に対する幕府の干渉はしだいに強まり，新年号は将軍の内定を経たうえで天皇が形式的に決定するという方式が室町幕府の下で固定化し，それが江戸幕府にも引きつがれた。…

※「改元難陳」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報