Leonard was the son of Domenico Casanova and Anna Maria Benza. Leonard's father was a ship captain whose family lived in Port Maurice on the northwestern coast of Italy. At 13, Leonard went to Rome to live with his uncle Agostino and study at the Jesuit Roman College. He was a good student and destined for a career in medicine. In 1697, however, he joined the Friars Minor. When he decided against medicine, his uncle disowned him. On 2 October 1697, he received the habit and took the name Brother Leonard. After making his novitiate at Ponticelli in the Sabine mountains, he completed his studies at St. Bonaventura on the Palatine at Rome.
After his ordination he remained there as professor, and expected to be sent on the Chinese missions. After ordination Leonard contracted a bleeding ulcer and was sent to his hometown where there was a monastery of the Franciscan Observants. After four years he was restored to health, and began to preach in Porto Maurizio.
The Great Missionary
Alphonsus Liguori called Leonard "the great missionary of the 18th century". He attracted large crowds and was invited to visit and preach in many places. Leonard spent over forty years preaching retreats, Lenten sermons and parish missions throughout Italy. His missions lasted 15 to 18 days, and he often stayed an additional week to hear confessions.
In 1720 he crossed the borders of Tuscany and held his celebrated missions in Central and Southern Italy. Everywhere Leonard made conversions, and was very often obliged both in cities and country districts to preach in the open, as the churches could not contain the thousands who came to listen. Pope Benedict XIV held him in high esteem both as a preacher and as a propagandist, and exacted a promise that he would come to Rome to die. Pope Benedict XIV appointed him to several complex diplomatic assignments. In Genoa and Corsica, in Lucca and Spoleto the citizens expected a bejeweled cardinal to represent the intentions of the pope. Instead, they were confronted by a humble, shoeless, muddy friar to confound their hostility and pride.
Leonard founded many pious societies and confraternities, and exerted himself to spread devotion to the Sacred Heart of Jesus, and the perpetual adoration of the Blessed Sacrament. He also began to insist that the concept of the Immaculate Conception of Mary be defined as a dogma of the faith.
The Franciscans had been the custodians of the Holy Sites in the Holy Land, including of the "Way of the Cross", since 1343. Though many saints were devoted to the Stations of the Cross, few if any did more to promote them than Leonard. As a Franciscan priest, he preached the Way of the Cross at missions for forty-three years and reportedly set up stations in 571 locations throughout Italy, including the Colosseum in Rome.
