When Constantine died, the 74-year-old Theodora returned to the throne despite fierce opposition from court officials and military claimants.

[4]: 503–504 As an eligible imperial princess, Theodora was considered as a possible bride for the Holy Roman Emperor in the west, Otto III, in 996.

[5]: 253, 259  Basil II prevented his nieces from marrying any of the Byzantine nobility, calculating that such a marriage would have given their husbands a claim on the imperial throne.

"[7]: 471  Theodora remained there for the next 11 years as Zoë managed the empire with her husbands Romanos III and, after his death, Michael IV.

This treatment of the legitimate heir to the Macedonian dynasty caused a popular uprising in Constantinople, and on 19 April 1042, the people revolted against Michael V in support of not only Zoë, but Theodora as well.

[7]: 496 Key members of the court decided that flighty Zoë needed a co-ruler, and backed the people's demand that it should be Theodora.

[7]: 496  Theodora, accustomed to a life of religious contemplation, rejected their pleas out of hand, and fled to the convent chapel to seek sanctuary.

[5]: 298–300 Zoë immediately assumed power and tried to force Theodora back to her monastery, but the Senate and the people demanded that the two sisters should jointly reign.

[5]: 301  With Michael V dealt with, Theodora refused to leave Hagia Sophia until she had received a formal invitation from Zoë, some 24 hours after they had been crowned.

[5]: 305 Although Theodora and Zoë appeared together at meetings of the Senate or when they gave public audiences, it was soon apparent that their joint reign was under considerable strain.

As Constantine lay dying, he was persuaded by his councilors, chiefly the logothetes tou dromou John, to ignore the rights of Theodora and to pass the throne to the doux (Duke) of the Byzantine Theme of Bulgaria, Nikephoros Proteuon.

She came out of retirement and convened the Senate, and the imperial guard proclaimed her "emperor" shortly before Constantine's death.

Nikephoros Bryennios, whom the western tagmata apparently wanted to proclaim emperor instead, was dismissed and exiled on Theodora's orders,[4]: 329 [8]: 597  after which she confiscated his estates and banished his supporters from court.

She damaged her reputation, however, with excessive severity toward private enemies and undue employment of such menials as Leo Paraspondylos as her advisors.

[7]: 528  Military and court offices were filled by her household eunuchs, and such able commanders as Isaac Komnenos were replaced with minor functionaries.

[7]: 528  Determined to centralize as much power in her hands as possible, she presided in person in the Senate and heard appeals as supreme judge in civil cases.