Empress Helen Dragas was a native of Serbia and mother of the last Byzantine Emperor, Constantine XI. She founded "Hope for the Hopeless," a home for the elderly at the Monastery of St. Patapios of Thebes (where her skull is currently kept). After her husband's death, she was tonsured a nun at the Monastery of St. Martha, taking the name Ipomoni (lit. Patience).
The date of the Fall of Constantinople and the death of her son is May 29th, and that is likewise the date of her Feastday.
Life of St. Ipomoni
St. Ipomoni as a Model for our Lives
Monastery of St. Patapios