His early studies were made in a Jesuit college in the city of Rome. Knowing that his vocation was to serve God as a Religious, he joined the Riformella, a society similar to the Friars Minor, introduced into Italy by Blessed Bonaventure of Barcelona in 1662. He received the habit in 1697, and after making his novitiate was sent to the principal house at Rome to complete his studies. After his ordination he suffered from ill health for a period of four years, during which time his superiors kept him in a monastery of the Franciscan Observants in his native city.
Upon his recovery, he began the work of giving missions, which he continued throughout his life. His first missions were given in his native city. From there he went into Tuscany, and his efforts in recalling sinners to penance were blessed by God with many noted and remarkable conversions. His missionary labors took him to all parts of Italy and the islands, and on many occasions he was compelled to preach outside the churches, on account of the immense crowds of people who came to hear him. He encouraged the people to lead pure and upright lives, and recommended to them in particular the adoration of the most Blessed Sacrament, and the devotion of the Way of the Cross.
Besides engaging in the work of the missions, St. Leonard found time to write a great many works, made up mostly of sermons, letters, books on the spiritual life, and devotional works of various kinds for the benefit of priests and people. Viewed from the exterior, we can see that he devoted his entire time to working in the vineyard of the Lord. From the interior, we can see him as the true man of God.
He died in Rome on November 26, 1751.
Illustration and text from Pictorial Lives of the Saints With Reflections for Every Day in the Year (New York: Benziger Bros., 1922).