Alphonse Ratisbonne was twelve years younger than Theodore, and did not know him well, but was hostile to his conversion to Christianity.
When he was 28, he was engaged to be married. Before the wedding he set out on a journey to Italy. Through an error in booking the tickets, he arrived in Rome in January 1842. There he went to visit the family of a friend of the Ratisbonnes who lived in Rome. The next day, he met the father of the family and who took him to the church of St Andrea dela Fratte. While he was waiting for his friend who was around Midday on 20th January. He underwent a sudden conversion experience - seeing Mary, the mother of Jesus as she appears on the Miraculous Medal.
Soon after his conversion, he was baptised and joined the Jesuits. He stayed in the Jesuits for 10 years and then began to work with his brother Theodore and the early sisters.
Alphonse felt very called to go to Jerusalem, and in 1856 he founded the Ecce Homo Convent on the Via Dolorosa in the Old City. This house was originally an orphanage but soon became a school for the local children.
In 1860 he opened a house in the village of Ein Karem which also started as an orphanage. Alphonse lived at Ein Karem for the last years of his life. He died on 6th May, 1884.