The last of eleven children, Mariana Fontaella, was born on January 7, 1661 into a noble family of Turin. At fourteen years, the young girl struggled hard to convince her widowed mother to allow her to become a nun and finally entered the monastery of the Discalced Carmelites of St. Christine, founded by the Princess of Savoy. On November 19th, 1675, Marianna received the Carmelite habit and was given the name, Mary of the Angels. She was professed in the following year.
Mary experienced a deep spiritual transformation after many trials and sufferings, and became well known in the city for her sanctity and virtues. With a dispensation she became Prioress at the age of thirty-three. During her life she had a reputation for holiness and wise counsel. She is credited for ending wars, for liberating Turin from the advancing French armies. In gratitude for this favor, the famous shrine at Superga was erected. Blessed Mary enabled the founding of the Carmel at Moncoglieri. She died in Turin on December 16th, 1717, on which day her feast is observed.