Rosemary Serio was born in Ostuni in the southeast of Italy on August 6, 1674 the day of the Feast of the Lord’s Transfiguration. Her parents were Antonio Serio - a professor of medicine, and Francesca Spennati. Rosemary’s christening name was Romana. She had seven sisters and many brothers.

Romana’s oldest sister, Magdalene, wanted to become a nun and live at the nearby Convent of Fasano which had been recently set up. 

When Anna Maria Semeraro received the third Order of the Discalced Carmelite habit, many other sisters started following her, so that Father Sante Mignozza - the spiritual director of the group, came up with the idea of gathering them into a convent (1681). 

The nuns gladly accepted Magdalene Serio, but with one request – that she would also allow her second sister, Romana, to enter too. On October 1st 1690 Romana received the Carmelite habit, and took the name of Rosemary (and then she added “of St. Anthony” in honor of her father).

The Mother Superior - Sister Cherubina of St. Joseph, and the Novice mistress were amazed by the spiritual maturity of Sister Rosemary. All through her novitiate, they continually gave her mortification. 

The nuns gladly accepted Magdalene Serio, but with one request – that she would also allow her second sister, Romana, to enter too. On October 1st 1690 Romana received the Carmelite habit, and took the name of Rosemary (and then she added “of St. Anthony” in honor of her father).

The Mother Superior - Sister Cherubina of St. Joseph, and the Novice mistress were amazed by the spiritual maturity of Sister Rosemary. All through her novitiate, they continually gave her mortification.

On an outbreak of pestilence which killed most of the population of Fasano, Rosemary’s superiors asked her to intercede with the Lord in order to protect the monastery. On that outbreak none of the nuns were affected by the plague.

She was deeply discerning God’s presence, and she prayed with an extraordinary intensity.  

Her Superior called a panel of theologians to examine her. Even though they declared themselves ‘satisfied’ with her conduct, Sr. Cherubina postponed Rosemary’s oblation for further four months to test her again, and to allow her parents to be present at the ceremony. Finally, on the Feast of Epiphany, Sister Rosemary was professed nun.

Rumors on this nun and her sanctity reached the General Vicar, and when a well-known confessor of cloistered nuns was passing by Fasano, the General Vicar asked him to interview Sister Rosemary.

He wrote a letter to the local bishop, and the General Vicar immediately ordered Rosemary to be imprisoned in the farthest cell away from the others, and to be fed only on bread and water. The entire monastery was in shock, but Sister Rosemary accepted this injustice with obedience. Finally she was released from her prison and she was able to return to the community.

At the age of twenty-five she was named Novice Mistress and by the age of twenty-eight she was unanimously chosen as Prioress (even if there were many other older sisters then her). 

Sister Rosemary accepted the role of Prioress at the condition that an older nun would be named over her: in this way, the older nun would have been able to charge her in the name of obedience.

On September the 8th - on Our Lady’s Birthday, she took charge of the monastery. Even if she was elected twice for the first three year terms, she continued to be elected by the other sisters who had to go to Rome each time for a dispensation.

Her prayer continued even as Prioress especially on the greater feasts of the liturgical year.

Four days before she died she gave an exhortation to the sisters and for the next few days she could be heard whispering: "Holy, holy, holy". This was the last thing she said before she died on May 9th 1726 at 11pm at 52 years old. She had been a religious for 36 years.