Demiana was becoming a beautiful young lady as she was growing up. When one of the young men asked for her hand in marriage, she refused to consider the matter and revealed to her parents that she wished to dedicate her life to the service of the Lord Jesus Christ. Her father was very pleased and complying with her wish, built her a special mansion north of the town. She lived there with forty other virgin friends, worshipping God and serving the surrounding community.

When Diocletian began his persecution on the Christians, he asked the Egyptian Prince and Noblemen, who did Marcus belong to and that he should offer incense to the Roman Gods. Marcus fearing the loss of his prestigous life, joined the idol worshippers.

When the news reached Demiana in her seclusion, she went and met with her father, expressing her deep dissapointment. Marcus regretted what he had done and went immediately to the Emperor and proudly declared his faith in the Lord Jesus Christ. Diocletian was infuriated and ordered that they cut off his head at once. And so Marcus recieved the crown of martyrdom. Later on, Diocletian wanted to know who made Marcus change his mind, and they told him that it was his daughter Demiana. So he ordered his officers to go to the Saint and the forty virgins and try to dissuade them from their faith. And if neither promises nor threats availed, she was to be put to death.

When Demiana heard the officers outside her palace, she said to her companions; "Whoever fears death, leave now." But they all stayed with her holding firm in their faith, praying together to their Saviour.

The officers tried persuasion at first, but St. Demiana and the forty virgins refused to denounce their faith. Therefore, they were tortured outrageously and inhumanely, but kept praying and praising God. During her suffering Demiana did not stop praying, encouraging her companions to endure the torment. Hundreds of those who witnessed what happened, confessed their faith and believed in the Lord Jesus Christ, recieving the crown of martyrdom.

God sent Archangel Michael, who visited Demiana three times and in every visit, he used to encourage her and heal her wounds. Finally, Demiana and the forty virgins were put to death. They recieved the crowns of martyrdom, chastity and endurance.

Later on, the cruel Emperor Diocletian died and the terrible persecution ended. When Emperor Constantine came to power, it happened that his mother, Queen Helens, heard the story of St. Demiana and found the bodies of St. Demiana and the forty virgins. She shrouded the bodies with expensive clothes and laid them in a vault. On top of the vault, she built an altar and a beautiful church which was consecrated by Pope Alexandros the 19th, on the 12th day of the Coptic month of Bashans, which is also the feast of Archangel Michael.

The original church was eventually destroyed but another has been rebuilt and still stands on the very same site to this day. Every year, many people visit St. Demiana's shrine, asking for her intercessions. The main season of visit is the period between 4th to 12th Bashans. (12th - 20th May).