Fujiwara no Senshi (藤原詮子)
FUJIWARA no Senshi (her given name can also be pronounced "Akiko") (962 - February 7, 1002) was the nyogo (a court title given to a consort of the Emperor) of the sixty-forth emperor, Emperor Enyu, in the Heian period. She was the mother of the 66th emperor, Emperor Ichijo (she also held the title Kokumo, meaning empress dowager). She took the title Tosanjoin upon becoming nyoin (or retired empress).
She was the second daughter of FUJIWARA no Kaneie, who held the titles Sessho, Kanpaku, and Chancellor of State, and Tokihime, the daughter of FUJIWARA no Nakamasa, who held the title Settsu no kami. Her maternal siblings were FUJIWARA no Michitaka, FUJIWARA no Michikane, and FUJIWARA no Michinaga who became Sessho in that order, and the wife of Emperor Reizei, Nyogo Fujiwara no Choshi (also pronounced as "Toko").
She married and entered the imperial court in August 978 and was named Nyogo on November 4 (by the old lunar calendar) of the same year. She was given the rank of Jushiinoge (Junior Fourth Rank, Lower Grade) in 980. On June 1 (by the old lunar calendar) of the same year, she gave birth to the first crown prince, Imperial Prince Kanehito (later Emperor Ichijo) at Kaneie's Higashi Sanjo dono palace. However, she was replaced as empress by Kanpaku FUJIWARA no Yoritada's daughter, FUJIWARA no Junshi (Nobuko), despite the fact that Senshi had given birth to Emperor Enyu's only child, and she secluded herself in her parental home of Higashi Sanjo dono, both she and her father hating the Emperor and refusing to respond to his summons. In addition, when Junshi became empress, Junshi's brother FUJIWARA no Kinto had stood in front of Higashi Sanjo dono, braggingly asking 'when will this nyogo become empress?' and earning the hatred of Kaneie and his daughter, Senshi.
("Okagami")
However, when Emperor Ichijo came into power, the situation drastically changed and she was made Empress Dowager on July 5, 986 (old lunar calendar). When the Cloistered Emperor Enyu (who had become a monk) passed away in February 991, she retired as the Empress Dowager on September 16 (old lunar calendar) of the same year and took the title of Tosanjoin, after the name of her residence, Higashi Sanjo dono. She was the first person to use a nyoin title.
She had a strong say in the court of Ichijo as Kokumo and often interfered in politics, leading FUJIWARA no Sanesuke to criticize her in his diary "Ouki," saying 'the Kokumo rules the court.'
In addition, there is a well known story that she used to favor her brother, Michinaga, who was four years younger, and when her older brothers, Michitaka and Michikane, passed away, she pushed for him to be appointed administrator over her nephew, FUJIWARA no Korechika, and later caused the downfall of her older brother's family. On the other hand, she was deeply religious and established Shinsho Gokuraku-ji and Jitoku-ji Temples. Furthermore, she took in MINAMOTO no Akiko, the youngest daughter of the overthrown MINAMOTO no Takaakira, having her marry Michinaga and adopted the second crown princess, Imperial Princess Bishi, when Ichijo's Empress FUJIWARA no Teishi (Sadako) died during a difficult labor.
She died in December 1002 at the palace of FUJIWARA no Yukinari, away from the imperial court, and was buried in Uji no Misasaki among the graves of the FUJIWARA clan of Uji Kowata.
There is a scene depicted in "Okagami" and "Eiga Monogatari," of Michinaga cradling her ashes during the funeral but this is just fiction - in reality, it was Senshi's nephew (Michikane's son), FUJIWARA no Kanetaka, who cradled her bones.