[11th or 12th century, Classical Numismatic Group, source: Wikimedia Commons]
Irene was born the daughter of Andronikos Doukas and Maria of Bulgaria. Through her parents she was related to both the Byzantine Imperial line and the rulers of Bulgaria. She officially married Alexios Komnenos at age 11, cementing the alliance between Alexios and the powerful Doukas family that supported Alexios in his bid for the throne. The former Empress, Maria of Alania, had also supported Alexios, and it was rumored after his coronation that he was carrying on an affair with her* and that the reason Irene was not immediately crowned as well was because his mother would rather have Maria as Empress again. Nevertheless, Irene and her family marshaled their strength and forced the issue, leading to her own coronation a week after her husband’s.
The couple ruled together for 37 years and had nine children. When Alexios went on campaign, Irene generally went with him. When she did stay behind, she acted as regent with Anna and her husband to advise her. She was very close with her eldest daughter and regarded her as a more worthy successor to Alexios than her son John, the assumed heir. Her insistence on this point eventually led to a rift between her and Alexios, on whose death in 1118 John took the throne.
Irene went into mourning, but it was not long before she reentered the political arena to support Anna in her bid for power. When they were discovered, John forced both his sister and his mother to retire from politics, causing Irene to enter the monastery of Kecharitomene, which she had founded a few years prior. It was here that she lived out the rest of her life as a nun. It was she, perhaps during these later years, who inspired Anna’s husband Nikephoros to start working on the history that Anna would later turn into her Alexiad. Irene died peacefully in 1138.
*Anna Komnene, Irene’s daughter, vehemently denies the rumor in her Alexiad, one of the major primary sources here.
Anna Comnena: The Alexiad - Internet History Sourcebooks Project
Empress Irene Doukaina, Typikon of Kecharitomene, 1110-1116, translated by Robert Jordan - Dumbarton Oaks
Irene Doukaina - Wikipedia