Footnote Slide 36. Condensed Visual Classroom Guide to Daikokuten Iconography in Japan. Copyright Mark Schumacher, 2017.
INTRODUCTION OF MIWA DEITY TO MT. HIEIScholars generally assume the Miwa deity (aka Ōmononushi, aka Ōnamuchi) was introduced to Mt. Hiei during the reign of Tenji 天智天皇 (r. 626–71). The prevailingview is that the Miwa deity was “invited” to Mt. Hiei around 663-667 CE, when Tenji moved his court out of the Yamato basin to the more secluded site of Ōtsu 大津 (nearMt. Hiei). In 667 CE, Tenji’s new palace was built just five kilometers south of Mt. Hiei. Before the court’s move to Ōtsu, one of the most important sites of court kamiworship was Mt. Miwa, located on the eastern edge of the Yamato plain. The Miwa deity hailed from Mt. Miwa and was perhaps Japan’s most powerful kami in thosedays. It is therefore “reasonable” to assume the Miwa deity was “invited” by Tenji’s court to reside near the new capital in Ōtsu. NONETHELESS, it is impossible to saywith certainty if the Miwa deity was installed at Mt. Hiei between 663-667 CE. It is safer to say the Miwa deity was “imported” to Mt. Hiei sometime in the 7th or 8thcenturies (probably before the Nara era). Saichō 最澄 (767-822), founder of Hiei’s shrine-temple multiplex, was certainly aware of the Miwa deity and actively venerated it.
• Writes Meri Arichi in Seven Stars of Heaven and Seven Shrines on Earth: The Big Dipper and the Hie Shrine in the Medieval Period, quote from pp. 203-204
Culture and Cosmos, Winter 2006, Vol. 10, pp. 195-216:
The origin of the [Hiei] shrine goes back to the local belief in the kami of the mountain Ōyamakui no kami 大山昨神. Archaeological evidences suggest that the earlyworship of kami began to be performed at this location from at least the 3rd or 4th centuries CE. According to the oldest surviving shrine record, Hiesha Negi
Kudenshō 日吉社禰宜口伝抄 (dated 1047), another kami, Ōnamuchi no kami 大己貴神 from Mount Miwa 三輪, was solicited to this location during the reign ofEmperor Tenji 天智 in the 7th century, and two shrine buildings were constructed in 669. The shrine legend claims that the third shrine, Jūzenji 十禅師, wasestablished when a kami called Jūzenji manifested himself in the form of a young boy in front of Saichō in 785, but as there is no contemporary textual evidence forthis claim, it is more likely that the story was a later invention. Such legends highlight the problem of researching the history of shrines in general, since the origins ofshrines were written long after the actual events. Saichō is also considered to be the patriarch who named the multiple kami of Hiei with the collective term Sannō,literally ‘Mountain King.’ The adoption of the name Sannō originates from the legendary Chinese deity Mountain King’ of Mount Tiantai. In the medieval period Sannō
was regarded as the protector of three sacred mountains, the Vulture Peak in India, Mount Tiantai in China and Mount Hiei in Japan. Cf. Hiesha Shintō Himitsuki(1571), by the shrine priest Hafuribe Yukimaro, in Shintō Taikei 神道大系, V.29, p. 331. For Hiesha Negi Kudenshō, see Shintō Taikei, V. 29, Jinja-hen, p. 3.
• Write Teeuwen and Breen (2010) in A New History of Shinto, pp. 71-74:

p. 71. At least until the reign of Tenji (r. 626–71), the hill of Miwa at the eastern edge of the Yamato basin was a major site of court kami worship. The deity enshrined
there was Ōnamuchi or Ōmononushi – identified with Ōkuninushi, Ōyamakui’s distant relative and the undisputed leader of the earthly deities. This deity shared manyof Ōyamakui’s characteristics. In Kojiki and Nihon Shoki (720), the kami of Miwa emerges as the prototypical earthly deity: a violent force that Yamato’s heavenly
dynasty struggled to control.
ap. 72-73. After a catastrophic defeat of Yamato forces waging war in Korea (in 663), Tenji decided to move his court out of the Yamato plain to the more secluded siteof Ōtsu on the southern shore of Lake Biwa. In 667 he built a new palace only 5 kilometers south of Hie, which now suddenly became the ritual site closest to the court.
In 671 Tenji died and was succeeded by his son, but in the following year, 672, Tenji’s brother Tenmu (r. 673–86) rebelled and took the throne after heavy fighting in theŌtsu/Hie area. After his victory, Tenmu moved the capital back to Yamato, where he ascended the throne in 673. All this made for a brief but intense incursion ofYamato power into the direct vicinity of Hie. These dramatic events marked the beginning of a new phase in the site’s development. There is no hard evidence as to thedate of the founding of the western compound at Hie, but it is clear that this event had its origins in Yamato. The main kami enshrined in this compound is none otherthan Miwa’s Ōnamuchi. It appears that by medieval times there were two legends about the appearance of this deity at Hie. One group of sources claims that the Miwa
deity was moved to Hie at the initiative of the monk Saichō (767–822), who turned Mount Hiei into a stronghold of Tendai Buddhism. However, it is hard to see whySaichō would have made such a move, since by Saichō ’s time Miwa had lost its position as the foremost protector of the imperial court to the Ise Shrines. Othersources, however, point at the years of Tenji’s rule in Ōtsu. In ancient poems written shortly before the move to Ōtsu, courtiers lamented that they would now no longerbe able to savor the familiar shape of Mount Miwa. If we take this as proof that Miwa was still important to the Yamato court at this time, it appears reasonable toassume that Tenji had the Miwa deity installed at Hie, where a related cult already existed.
ap. 74. Reconstructing the Hie traditions after the disaster of 1571, Ushimaru’s descendant Yukimaru noted: “This shrine complex was begun with the construction ofŌmiya [i.e., Great Hie]. Ninomiya and Hachiō-ji are older, but they had no shrine buildings. Kotomitachi [that is, Ushimaru] was the first to construct a shrine hall here [atHie]. This happened during the reign of Emperor Tenji.” (ST Hie: 331)