Paul Jerome Casanova was born in Port Maurice on the Italian Riviera and received his education from the Jesuit Fathers in Rome He entered the Franciscans when he was twenty-one, taking the name Leonard. He was ordained in 1703. He was assigned to the Franciscan monastery at Florence and for a time was superior of the monastery. Leonard was known best for his missionary efforts throughout Italy. His sermons frequently had to be given in the open air because no church would hold the vast crowds that came to hear him. He made his missionary journeys on foot, as St. Francis had done.
Leonard constantly preached the Way of the Cross, a devotion not very well known at that time. He set up the stations at every place he preached. In 1750 one of his ambitions was realized when Pope Benedict XIV permitted him to set up the Stations of the Cross in the Colosseum. He also encouraged exposition of the Blessed Sacrament, devotion to the Sacred Heart, and devotion to the Immaculate Conception, all of which were far less widespread then than they are today. He made great efforts to have the Immaculate Conception defined as a dogma of faith. This came about a century after his death.
In spite of his missionary activity Leonard found time to w many letters, sermons, and devotional treatises. He is highly referred to as an ascetic writer. Today, the Catholic Church celebrates the feast day of St. Leonard of Port Maurice on November 26th