Theodora Porphyrogenita, sometimes numbered Theodora III, was Byzantine Empress from 19 April 1042 to her death on 31 August 1056. She was sole empress regnant from 11 January 1055. She was born into the Macedonian dynasty that ruled the Byzantine Empire for almost two hundred years.
Theodora became involved in political matters only late into her life. Her father Constantine VIII was co-ruler of the Byzantine Empire for 63 years then sole emperor from 1025 to 1028.