Stories of the Japanese 00447 [Late Heian Period] Prince Mochihito's Imperial Mandate

At this point, I must introduce a figure named Prince Mochihito (1151–1180), the third son of the Retired Emperor Go-Shirakawa.
Despite being a son of Go-Shirakawa, Prince Mochihito was long neglected, never even receiving the title of Imperial Prince, let alone a chance to succeed to the throne, because his mother, Fujiwara no Nariko (d. 1177), came from a family with no political power.
Only princes with Taira blood, such as Takakura and Antoku, were favored, while he, born of a Fujiwara connection, remained stagnant. Perhaps it was this frustration that built up. On April 9, 1180 (the 4th year of Jisho), Prince Mochihito secretly issued a ryoji (an imperial mandate from a member of the imperial family) ordering the 'overthrow of the Taira clan' and commanded that it be delivered to the eastern provinces.
The eastern provinces were home to many warriors who felt indebted to Minamoto no Yoshiie in the past, and more recently, to Minamoto no Yoshitomo. Prince Mochihito believed there must be many who were smoldering with dissatisfaction at not being able to obtain official court ranks under the Taira regime.
The person who traveled through the eastern provinces to deliver this mandate from Prince Mochihito was Minamoto no Yukiie (d. 1186), a younger brother of Yoshitomo. Yukiie was the tenth son of Tameyoshi and was initially named 'Yoshimori.' Having grown up in Shingu (Shingu City, Wakayama Prefecture), he was also called 'Shingu Juro Yoshimori.' Yukiie disguised himself as a yamabushi (mountain ascetic) to travel through the east, and from this point on, he played the role of contacting key members of the Minamoto clan one after another to distribute the mandate.
Although Prince Mochihito's mandate was intended to be top secret, the information naturally leaked as it spread through the eastern provinces. On May 15, the Kumano Betto, Tanzo (1130–1198), learned of the existence of this mandate. Since the Kumano Hongu Taisha received generous support from the Taira, they were naturally on the Taira side.
On the other hand, the monks of the Kumano Nachi Taisha, located not far from the Kumano Hongu Taisha, did not enjoy the benefits of the Taira and harbored resentment over the current situation where only those with Taira connections could be promoted. In other words, a conflict broke out within the three Kumano shrines.
Tanzo and his forces from the Kumano Hongu Taisha rushed to the coast with 3,000 cavalry. They were met by 2,000 monks from the Kumano Nachi Taisha.
The first battle of the Genpei War had finally begun. It is recorded that the sound of arrows being fired by both armies never ceased, and the flashing of swords was like lightning.
After fighting for a full day, the victors were the Kumano Nachi Taisha side, which is to say, the Minamoto side.
Tanzo and his men barely escaped with their lives, fleeing back to the Kumano Hongu Taisha.