Fujiwara no Shōshi (藤原彰子?, 988–1074), also known as Jōtōmon-in (上東門院?), the eldest daughter of Fujiwara no Michinaga, was Empress of Japan from c. 1000 to c. 1011. Her father sent her to live in the Emperor Ichijō's harem at age 12. Because of his power, influence and political machinations she quickly achieved the status of second empress (中宮 Chūgū?). As empress she was able to surround herself with a court of talented and educated ladies-in-waiting such as Murasaki Shikibu, author of The Tale of Genji.
By the age of 20, she bore two sons to Ichijō, both of whom went on to become emperors and secured the status of the Fujiwara line. In her late 30s she took vows as a Buddhist nun, renouncing imperial duties and titles, assuming the title of Imperial Lady. She continued to be an influential member of the imperial family until her death at age 86.
In the middle of the 9th century Fujiwara no Yoshifusa declared himself regent to Emperor Seiwa—his young grandson—the Fujiwara clan dominated court politics until the end of the 11th century, through strategic marriages of Fujiwara daughters into the imperial family and the use of regencies. Fujiwara no Michinaga had four daughters he arranged to marry to emperors. At this period emperors held little power, holding a nominal position for rituals, and often too young to make decisions. In their stead, the top position in the power structure was held by a regent, with power often measured by the how closely the regent was tied by family relationships to an emperor. In 995 Michinaga's two brothers Fujiwara no Michitaka and Fujiwara no Michikane died in rapid succession, leaving the regency vacant; Michinaga won a power struggle against his nephew Fujiwara no Korechika, brother to Emperor Ichijō's wife Teishi, aided by his sister Senshi (mother to Emperor Ichijō, Emperor En'yū's wife). Because Teishi supported Korechika—later discredited and banished from court—her base of power disintegrated.