When was the sister of Theodora Porphyrogenita died who was reigned as Byzantine Empress alongside her sister?
Theodora Porphyrogenita (11th century) Theodora Porphyrogenita (Greek: Θεοδώρα, "Theodōra" ; AD 980 – 31 August 1056) was a Byzantine Empress born into the Macedonian dynasty that had ruled the Byzantine Empire for almost two hundred years. She was co-empress with her sister Zoë for two months in 1042 and sole empress regnant from 11 January 1055 to 31 August 1056. She was the last of the Macedonian line, and upon her death the empire entered a period of decline that lasted until the ascension of Alexios I Komnenos in 1081.
Justin II Justin II (Latin: "Flavius Iustinus Iunior Augustus" ; Ancient Greek: Φλάβιος Ἰουστίνος ὁ νεώτερος ; c. 520 – 5 October 578) was Eastern Roman Emperor from 565 to 574. He was the husband of Sophia, nephew of Justinian I and the Empress Theodora, and was therefore a member of the Justinian Dynasty. His reign is marked by war with the Sassanid Empire and the loss of the greater part of Italy. He presented the Cross of Justin II to Saint Peter's, Rome.