Ipomoni of Loutraki
The holy and right believing Empress Augusta Helen Palaiologos, also known by her monastic name of Ipomoni, was the wife of Emperor Emmanuel Palaiologos of the Eastern Roman (Byzantine) Empire and mother of the last emperor, Constantine XI Palaiologos. She was known for her piety and works in establishing the home for old people, called The Hope of the Despaired. Her memory is commemorated March 13, the day she fell asleep, and May 29, the day Constantinople fell and the death of her son Constantine XI Palaiologos.
Augusta Helen Palaiologos was the daughter of the emperor of Slavs Constantine Dragasis. She became empress of Byzantium as the wife of Emmanuel Palaiologos. She had six children. As empress she was noted for her pious works. She was pious and honored God, and related with people in a godly manner. She was well known for her piety, wisdom, and justice. Her husband (as a former emperor) became a monk with the name Mathieu. After his death she became a nun at the Monastery of Kira–Martha, taking the name Ipomoni (or Hipomoni). She helped to establish a home for old people, with the name "The Hope of the Despaired". The home was located at the Monastery of St. John of the Stone where the relics of St. Patapius of Thebes are also kept.
She died on March 13, 1450. Her son, Emperor Constantine XI Palaiologos, died in the final charge  during the fall of Constantinople on May 29, 1453, while many other Christians were slaughtered by the Ottoman Turk forces of Sultan Mehmet II throughout the city as well as inside the famous church.