Takashina Clan (the clan of which the first son of Emperor Tenmu, Prince Takechi [Takechi no Miko] w (高階氏)
Takashina clan is the clan of which the first son of Emperor Tenmu, Prince Takechi, was the ancestor.
When Conspiracy of Nagayao occurred, Prince Isobe, a son of Prince Kuwata [Kuwata no Miko] who killed himself with his father Prince Nagaya (his mother Minabe no Himemiko), was spared his life and Prince Mineo, a grandson of Prince Isobe became subjects of the state to be granted the hereditary title of TAKASHINA Mahito in 844. Prince Asukabe who was a paternal half-brother of Prince Kuwata (his mother was FUJIWARA no Nagako, a daughter of FUJIWARA no Fuhito) and some others were also granted the hereditary title of TAKASHIMA no Mahito; however, each lineage ended at early stage.
Mineo became Ise no Gon no kami (Provisional Governor of Ise Province) and served Saigu (Imperial Princess appointed to serve the deities of the Ise-jingu Shrine), Imperial Princess Tenshi (also known as Imperial Princess Yasuko). According to some people, Mineo adopted a boy named TAKASHIMA no Morohisa, who was born between the Imperial Princess and ARIWARA no Narihira by adultery, and had him succeed Mineo. People of the Takashina clan came to refrain from going and worshipping at Ise-jingu Shrine afterward. However, some people consistently think this 'Moronao being illegitimate child' theory is absolutely groundless.
At the time of TAKASHINA no Naritada, when his daughter TAKASHINA no Kishi became the legal wife of FUJIWARA no Michitaka and bore a daughter FUJIWARA no Teishi, who later became the chugu (the second consort of an emperor) of Emperor Ichijo, the Takashina clan enjoyed sudden prosperity. However, enthronement of the Imperial Prince Atsuyasu whom Teishi bore was interfered by FUJIWARA no Michinaga and the descendants of Naritada fell along with the Nakanokanpaku family. The advice of FUJIWARA no Yukinari that the enthronement of Imperial Prince Atsuyasu, to whom blood of the Takashina clan was flown, would cause the anger of Ise-Jingu Shrine, was strong trigger for it.
The lineage of Naritada's younger brother TAKASHINA no Toshitada approached Michinaga, and built power as zuryo (provincial governor). The representative people in this lineage include TAKASHINA no Nariakira who was called Yoku-daini (Senior Assistant Governor General of desire), TAKASHINA no Tameie and his son TAKASHINA no Tameakira who executed construction of Hossho-ji Temple as a trusted vassals of the Cloistered Emperor Shirakawa. During the period when the Cloistered Emperor Goshirakawa was in power, the close adviser TAKASHINA no Yasutsune of the ministry of the Treasury, a favorite mistress TAKASHINA no Eishi were active. After them, the clan didn't have influential people then fell to obscurity; after TAKASHINA no Hirotsune in the period of the Northern and Southern Courts in Japan, no court nobles came from the Takashina clan. However, as a samurai family, the clan has been very prosperous; for example, the Ko clan who has been the steward of the Ashikaga family for generations came from the Takashina clan. KO no Muronao who was the steward of Muromachi bakufu (Japanese feudal government headed by a shogun) and Yoshiharu HORIO who served Nobunaga ODA and Hideyoshi TOYOTOMI and became daimyo (Japanese feudal lord) were to be said the descendant of the Takashina clan.