Imperial Prince Koretada (是忠親王)
Imperial Prince Koretada (857 - December 18, 922) was a member of the Imperial Family during in the early Heian period. His father was Emperor Koko, and his mother was Princess Hanshi. His brothers-uterine were Imperial Prince Koresada and Emperor Uda. His children were Prince Tadamochi, MINAMOTO no Masaakira and Princess Koshi (also pronounced as Yoshiko) who were the ancestors of the Minamoto and the Taira clans.
On March 23, 870 during the era of Prince Koretada, he was demoted from nobility to subject with his brother, Prince Koresada, and his paternal brothers, and referred to himself as MINAMOTO no Koretada. On January 24, 877, he was promoted from Sani (courtier without post) to Jugoinojo (Junior Fifth Rank, Upper Grade). After serving as jiju (a chamberlain) and at Emonfu (Headquarters of the Outer Palace Guards), his position was revised from Nisei Genji (second generation of the Minamoto clan) to Issei Genji (Emperor's son who went out of Imperial Family and had Genji name) on May 15, 884 soon after his father, Emperor Koko, ascended the throne, and took up his residence in the Sakyoichijo district. At this time, his younger brother-uterine, Prince Sadami (Emperor Uda), and his three younger sisters-uterine were also demoted from nobility to subject. He was given the rank of Shoshiinoge (Senior Fourth Rank, Lower Grade) on June 29, and was appointed as Sangi (councillor) on July 8. On February 8, 885, he concurrently served in Omi Province, and thereafter, he was transferred to Mutsu-Dewa Azechi (local inspector of Mutsu and Dewa Provinces). He rose to Chunagon (vice-councilor of state) in 891; however, he became Sanbon Shinno (the third-ranked Imperial Prince) as the first prince of Emperor Koko because it was decided that a brother-uterine of Emperor Uda who had already regained his position in the Imperial Family and ascended the throne in the same year. He was appointed as Shikibukyo (Minister of the Ministry of Ceremonies) as a successor of Imperial Prince Motoyasu who died in 901, and thereafter, he became Ippon Shinno (the first-ranked Imperial Prince). He became a priest in 920, and died due to disease two years later.