Ichijō came to the throne at six years old after his seventeen-year-old cousin Kazan was tricked into abdicating. He reigned for twenty-five years, and was sovereign during the years of Murasaki's experience at court.
During his brief reign Kazan showed indications that he had ideas about keeping imperial power—rather than submitting completely to the will of the regent. For this, he was manoevered out. The regent, Kane'ie, was confident he could completely control his young grandson Ichijō. Although power had gradually been seeping out of the imperial person into the figure of the regent, from Ichijō’s time, the transfer was complete. The emperor had become a figurehead.
There are several places in Murasaki's story where we see Ichijō chafing under the regent Michinaga's thumb, but ultimately he could do nothing about it. Ichijō was married to Michinaga's eldest daughter Shōshi, by whom he had two sons, Atsuhira (whose birth is elaborately described in Murasaki's Diary) and Atsunaga.
Both sons succeeded to the throne in order as Emperor Sanjō and Emperor Go-Ichijō.