Toei Daio (東叡大王)

Toei Daio is one of the honoric titles for Sanzan Kanryo no miya. Amongst educated people with kanbun (Chinese classics) knowedge in the Edo period, he was called as such in kanbun style.
(Refers to 'Imperial Princess in Toeizan Kanei-ji Temple')

The kanzu (a leader) of Ueno Toeizan Kanei-ji Temple which was one of the miya-monzeki (temples headed by imperial princes) in the Edo period, doubled as the head priest of Nikko-zan Rin-noji Temple and sometimes served for Tendai-zasu (head priest of the Tendai sect) of Enryaku-ji Temple on Mt. Hiei. Also, the kanzu was called Sanzan Kanryo no miya because they were all from Sanzan Kanryo no miya or were Imperial princes. It was believed that this was a strategy of the Tokugawa shogunate to obtain the Imperial lineage in Kanto. In doing so, the Shogunate was then able to position the Imperial court and the Emperor's enemy in such a way as to make it appear that this was just an internal struggle of the Imperial court; this strategy was actually used for the Tobu Emperor's enthronement at the end of Edo period.

The strategy had various names such as 'Sanzan Kanryo no miya,' 'Nikko no miya,' 'Ueno no miya,' 'Toei Daio,' and so on. It was also called 'Rinno-ji Temple sama' by the Imperial Court and the court nobles, 'Nikko Mikado no kami sama' by the Edo shogunate and samurai, and 'Ueno no miya sama' by the Edo people. It was also referred to as Toei Daio in kanbun.

This governance continued for 13 generations. Only Ueno no miya (the leader of Kanei-ji Temple) and Nikkogu (head priest of Nikko-zan Rin-noji Temple) in the 7th generation were not the same person; however, because the Nikkogu 7th was reappointed as the 5th for a second term, the total number of people was not 14. The appointed leaders for the temples were: 3 people from Kanin-no-miya, 2 people from Fushimi no Miya, 3 people from Arisugawa no Miya, and the others were all Imperial princes.

Most of the appointed leaders lived in Kanei-ji Temple and stayed in Nikko for three months per a year and some of them stayed in the Kansai region.

There were some exceptions in this succession, as there were some individuals who did not assume the Tendai-zasu position, and 4 people out of 13 generations did not double as the Tendai-zasu position due to premature deaths or short reign. The last generation, Imperial Prince Kitashirakawanomiya Yoshihisa, was also one of those who had a short reign: he did not assume the Tendai-zasu position due to the Boshin War. The kanzu (leader) of Ueno Toeizan Kanei-ji Temple and the chief priest of Nikko-zan Rinno-ji Temple simultaneously resigned and assumed the other's position. Because the Tendai-zasu position could be appointed by other Buddhist monks, there were some phases in their reign periods that they were not being Tendai-zasu.

Misunderstanding of Tendai-zasu
Some head priests did not assume the Tendai-zasu position during the Rinojinomiya reign; however, as it was a ceremonial position miya-monzeki consistently had actual authority under the name of Sanzan Kanryo no miya.

In other words, it was Toeizan Kanei-ji Temple who controlled theTendai sect in the Edo period but not Enryaku-ji Temple on Mt. Hiei. Therefore, 'Tendai-zasu' in this case, accurately means zasu (a head priest) of a temple called Enryaku-ji Temple on Mt. Hiei. After the Meiji period, the top position of theTendai sect returned to Mt. Hiei; however, for the convenience of counting the positions before and after the Edo period (from the Nara period to modern age), it was called 'Tendai-zasu' although in actuality it was different from the Edo period.

The Tendai-zasu position had a short reign and a quick turn-over. In other words, because of the above reasons, although many Buddhist monks who were not Rinnoji no miya (title given to imperial princes who had entered the priesthood) became Tendai-zasu, they were just head priests of the temple on Mt. Hiei, not of the Tendai sect as a whole. Due to individual reasons, four Rinnoji no miya, the 2nd, the 7th (Ueno no miya), the 11th, and the 13th, were not appointed as zasu of Enryaku-ji Temple on Mt. Hiei officially; however, it did not change the fact that they controlled the Tendai sect as the top of Kanei-ji Temple. This history is slightly complicated; however, zasu of Enryaku-ji Temple on Mt. Hiei in the Edo period were also called Tendai-zasu by convention.