[3] While her mother and her grandmother lived in Carthage, they came into contact with Augustine of Hippo, who helped them to follow the path of a religious life.
Demetrias, who was about fifteen years old in 413, was to be married, but she secretly followed an ascetical way of life, influenced by Augustine.
However, as her marriage was approaching, she decided to tell her mother Iuliana and her grandmother Proba about her intention to renounce to marry and to take the veil.
To help her in her spiritual life, Iuliana and Proba asked several churchmen to send Demetrias advice.
During this time she received the Epistula ad Demetriadem de vera humilitate, written in 440 by Pope Leo I or, according to recent studies, in 435 by Prosper of Aquitaine, and attacking Pelagius' doctrine on the basis of Augustine.