Mary was a slave of Tertullus, a Roman official. She was brought up as a Christian, and was the only Catholic in the house. When she was older, she prayed much and fasted often, especially on festivals when the pagan idols were given greater honor. Her mistress did not like this type of behavior, but she liked Mary because the girl was a good worker, who always kept herself busy.
Emperor Diocletian had issued his edicts against Christians. Senator Tertullus and his wife, who were Black, became fearful for Mary and themselves. He later caused her to be unmercifully whipped, and then to be locked up in a dark cellar for thirty days, where no other sustenance was allowed her but bread and water. Prayer, in the mean time, was her comfort and strength, and it was her joy to lose all the favour she could promise to herself in this world, and to suffer torments for Christ.
Later, the Prefect found out what had been done to Mary, and Tertullus was charged with hiding a Christian in his house. The young girl was then handed over to the Prefect. When the crowd of people heard Mary confess the Holy Name of Christ, they cried out, "Burn her alive! Burn her alive!"
Mary was calm. She stood there praying, "Dear God, please make me strong in the Faith and help me to persevere as a good Christian, until my death." Then she said to the Judge,
"The God whom I serve is with me. I do not fear your torments, which can only take away a life that I am ready to lay down for Christ."
The Judge then commanded that Mary be tortured. Mary was placed on the dreaded and deadly rack to be stretched and tortured. But she was tortured with such cruelty, that the people standing nearby cried out, "We cannot bear to see this poor girl treated with such cruelty! Release the girl! Release the poor girl!"
The Judge then handed Mary over to a soldier. The good soldier saw that the poor girl was helpless and allowed her to escape. St. Mary lived the rest of her life doing everything for God, and she died a natural death, possibly in the 4th Century. She is called a Martyr, in the Roman Martyrology, because of the sufferings she bore for the sake of Christ.
Hyman, M. (1988). Blacks Who Died For Jesus: A History Book. Winston-Derek Publishers.