Onshi shared her name with her elder sister, Fujiwara no Onshii (882 – 907), who was the wife of Emperor Uda of Japan and the adoptive mother of Emperor Daigo.
In 930, her spouse, the retired Emperor Daigo, as well as her father-in-law, the retired Emperor Uda, died, leaving Fujiwara no Onshi in a very influential position as the mother of the young Emperor Suzaku as well as the Crown Prince Murakami. This position allowed her to become the Head of the Imperial Family, and she institutionalized the role of the Emperor's mother and her office as synonymous with the caretaker of a child emperor.[2]
She continued to live with Emperor Suzaku after he became an adult and married, retaining her influence. During the reign of her next son, Emperor Murakami, she maintained peace within the Imperial House by acting as a mediator between her sons, the emperor and the retired emperor. In 950, she secured the appointment of prince Noriki as crown prince.
Notes
^Fr?d?ric, Louis; Louis-Frédéric (2002). Japan Encyclopedia. Harvard University Press. ISBN 9780674017535.
Unless otherwise noted (as BC), years are in CE / AD1 individuals that were given the title of empress posthumously
2 individuals elevated to the rank of empress due to their position as honorary mother of the emperor
3 Shōshi served briefly as honorary empress for her younger brother Emperor Go-Daigo
Unless otherwise noted (as BC), years are in CE / AD1 individuals that were given the title of empress dowager posthumously
2 title removed in 896 due to a suspected affair with head priest of the Toko-ji Temple; title posthumously restored in 943
3 was made High Empress or de jure empress dowager during her husband's reign
