Marie Alphonse Ratisbonne was born into a wealthy Jewish family in 1814. When Alphonse's brother converted to Catholicism and became a priest, the family reacted negatively, and Alphonse’s disdain for the Catholic Church was further hardened. While on vacation in Rome, Alphonse became friends with Baron Theodore de Bussières, whose personal mission was to convert every person he met. The Baron made a proposition to Alphonse: Wear the Miraculous Medal and say the Memorare every morning and see if something happens. Alphonse agreed. The Baron called upon many friends to say extra Memorares for Alphonse’s conversion. A few days later, while at the basilica of St. Andrea delle Fratte in company with the Baron, Alphonse experienced the following, taken from his account on Jan 20, 1842:
"I was scarcely in the church when a total confusion came over me. When I looked up, it seemed to me that the entire church had been swallowed up in shadow, except one chapel. It was as though all the light was concentrated in that single place. I looked over towards this chapel whence so much light shone, and above the altar was a living figure, tall, majestic, beautiful and full of mercy. It was the most holy Virgin Mary, resembling her figure on the Miraculous Medal. At this sight I fell on my knees right where I stood. Unable to look up because of the blinding light, I fixed my glance on her hands, and in them I could read the expression of mercy and pardon. In the presence of the Most Blessed Virgin, even though she did not speak a word to me, I understood the frightful situation I was in, my sins and the beauty of the Catholic Faith."
The Baron found Alphonse on his knees, sobbing. When asked what happened, Alphonse explained he could only recount the event on his knees to a confessor. Eleven days later Alphonse received the sacraments of Baptism, Confirmation, and first Holy Communion. In February of 1842, the Vatican conducted an investigation which concluded that Alphonse’s conversion was miraculous.