The first mention of the kami Oyamakui is recorded in Kojiki, written in the 8th century AD, which states that this god resides at Mount Hiei, which is located immediately to the east of Hiyoshi Taisha.

This kami was relocated from the summit of the mountain to its present location in the seventh year of the reign of the semi-legendary Emperor Sujin, or 90 BC per the traditional calendar.

As missionaries from Enryaku-ji built Buddhist temples all across Japan, they also spread the faith in the "Sanno Gongen" and the Hie kami.

It became the practice of the warrior-monks from the temple to carry a mikoshi portable shrine from Hie Taisha into the capital and to riot to enforce their political will.

Toyotomi Hideyoshi had a deep faith in the Sanno Gongen, as his childhood name was "Hiyoshi Maru" and his nickname was "monkey", an animal which was considered to be the spiritual messenger of the Hie kami.

Hie Taisha was at the forefront of this effort, and was one of the first to burn or otherwise dispose of its Buddhist statuary, ritual implements and scriptures.