"Theodosius II was made Emperor of the Eastern Roman Empire, at seven years of age. On July 4, 414 a fifteen-year-old Pulcheria proclaimed herself regent over him, then thirteen years of age, and made herself Augusta and Empress of the Eastern Roman Empire.
Theodosius II died on July 26, 450, and Pulcheria soon married Marcian on November 25, 450. Marcian and Pulcheria were proclaimed Emperor and Empress of the Eastern Roman Empire. Three years later, in July 453, Pulcheria died and was later made a saint by the Church.[2] Pulcheria is known to have held a significant amount of power in her brother's reign as emperor. Pulcheria was also the greatest influence over the church and theological practices of this time by presiding and guiding two of the most important Councils in Church history( Ephesus and Chalcedon) , including over anti-pagan policies, church-building projects, and the debate over the Marian title Theotokos ("Birth-giver to God")."
http://en.wikipedia.org/wiki/Pulcheria
"Irene of Athens or Irene the Athenian (Greek: Εἰρήνη ἡ Ἀθηναία) (c. 752 – 9 August 803) is the commonly known name of Irene Sarantapechaina (Greek: Εἰρήνη Σαρανταπήχαινα), Byzantine empress regnant from 797 to 802."
http://en.wikipedia.org/wiki/Irene_of_Athens
There's others, like Empress Theodora, or the breakaway queen Zenobia, or the unofficial power of Livia, whose husband was Augustus. I do note it seems easier to find powerful 'Roman' women in the Christian Byzantine empire.
Theodosius II died on July 26, 450, and Pulcheria soon married Marcian on November 25, 450. Marcian and Pulcheria were proclaimed Emperor and Empress of the Eastern Roman Empire. Three years later, in July 453, Pulcheria died and was later made a saint by the Church.[2] Pulcheria is known to have held a significant amount of power in her brother's reign as emperor. Pulcheria was also the greatest influence over the church and theological practices of this time by presiding and guiding two of the most important Councils in Church history( Ephesus and Chalcedon) , including over anti-pagan policies, church-building projects, and the debate over the Marian title Theotokos ("Birth-giver to God")."
http://en.wikipedia.org/wiki/Pulcheria
"Irene of Athens or Irene the Athenian (Greek: Εἰρήνη ἡ Ἀθηναία) (c. 752 – 9 August 803) is the commonly known name of Irene Sarantapechaina (Greek: Εἰρήνη Σαρανταπήχαινα), Byzantine empress regnant from 797 to 802."
http://en.wikipedia.org/wiki/Irene_of_Athens
There's others, like Empress Theodora, or the breakaway queen Zenobia, or the unofficial power of Livia, whose husband was Augustus. I do note it seems easier to find powerful 'Roman' women in the Christian Byzantine empire.