Definition:

Gibbon tells us Pulcheria, Augusta 'empress' from 414-453, was the first woman the Eastern Roman Empire accepted as ruler. Another first -- the reverse of a solidi coin from 450-453 depicting a Roman victory appears to include Pulcheria as one of the victors. She is also counted a Catholic and Orthodox saint.

Pulcheria was the oldest sister of Emperor Theodosius II (10 April 401 - 28 July 450).

They were offspring of Emperor Arcadius and Aelia Eudoxia. When Arcadius died in 408, Theodosius II became emperor, although he was still young. In July 414, Pulcheria was declared Augusta and from this time started having a heavy influence on the Eastern emperor, acting as regent and dictating the education of her brother, and later, probably, selecting Theodosius' successor, her future husband, the Emperor Marcian.

Pulcheria is renowned for her vow of celibacy. Not only did she take such a vow, but she persuaded her two younger sisters to do the same. This meant there would be no contender for the throne and no one to mitigate Pulcheria's heavy influence on her brother (until he took a wife). Along with the vow to remain virgins, the palace became very religious, with holy men and bishops in attendance. Pucheria commissioned church building and collected religious relics.

References:

• _{Theodosian Empresses: Women and Imperial Dominion in Late Antiquity, by Kenneth G. Holum}
  
• _{"Antiochus the Praepositus: A Persian Eunuch at the Court of Theodosius II
  Geoffrey Greatrex and Jonathan Bardill
  Dumbarton Oaks Papers, Vol. 50 (1996), pp. 171-197.}
  

• _{"The Ivories of Ariadne and Ideas about Female Imperial Authority in Rome and Early Byzantium"
  Diliana Angelova
  Gesta, Vol. 43, No. 1 (2004), pp. 1-15.}
  
• _{The Cambridge Ancient Hitory: The Late Empire, A.D. 337-425}
  
• _{The Prosopography of the Later Roman Empire, by Arnold Hugh Martin Jones.}
  
• _{Pulcheria, by Ada B. Teetgen}
  

Examples:

Pulcheria was in communication with Cyril of Alexandria of Hypatia fame.