Background
Anna Diogenissa was born in the Byzantine capital Constantinople sometime before or, at the latest, nine months after the death of her father Constantine Diogenes at Antioch in 1074. Her mother was Theodora Komnene, a daughter of the powerful noblewoman Anna Dalassena and John Komnenos, and hence sister to the future emperor Alexios I Komnenos (r 1081–1118).