Diplomatic Bluebook 2020
Opening Spetial Feature
From Heisei to Reiwa: Ceremonies of the Accession to the Throne
On May 1, His Majesty the Emperor of Japan acceded to the Throne, and the era name changed from Heisei to Reiwa. This marked the first imperial succession by abdication in approximately 200 years.
The most important ceremony of the Accession to the Throne is the Ceremony of the Enthronement of His Majesty the Emperor at the Seiden (State Hall), in which His Majesty the Emperor proclaims his enthronement and receives felicitations from representatives in Japan and overseas.
Japanese and foreign guests were invited to the Ceremony of the Enthronement at the Seiden held on October 22. While heads of State, envoys, their spouses, and others from 160 countries and organizations attended the Heisei imperial succession, the Reiwa imperial succession was represented by 191 countries, organizations, and others. Foreign guests also attended the Court Banquet after the Ceremony of the Enthronement and the Banquet hosted by the Prime Minister and his spouse.
With many foreign dignitaries visiting Japan, the events offered an opportunity to acquaint a wider circle of people across the globe with the linkages between the Imperial Family and the world.
Books of celebration for the new Emperor were opened at approximately 230 Japanese Embassies, Consulates, and other missions overseas.
Messages congratulating His Majesty's accession to the Throne were received from all over the world, including royal families and dignitaries with ties to the Imperial Family who signed the books of celebration.
* Photos on page 3: Secretariat for the Ceremonies of Imperial Succession, Cabinet Office
Key Events of the Accession to the Throne
Accession to the Throne by His Majesty the Emperor
Ceremony of the Enthronement of His Majesty the Emperor at the Seiden
Court Banquet after the Ceremony of the Enthronement
(Day 1: Foreign guests)
Banquet hosted by the Prime Minister and his spouse
Imperial Procession by motorcar after the Ceremony of the Enthronement
For messages from foreign dignitaries who attended the Ceremonies of the Accession to the Throne
https://www.kantei.go.jp/jp/content/kansou.pdf (Japanese only)