Paolo Casanova was born at Porto Maurizio on the Ligurian coast and entered the Reformed Franciscans at Rome in 1697, taking the religious name Leonardo. He was ordained in 1703 and assigned in 1709 to the small reformed Franciscan house at San Francesco del Monte in Florence, from which he travelled for the next forty-two years as the principal Italian wandering preacher of the early-to-mid 18th century — preaching about 350 documented missions across Tuscany, Umbria, the Marche, the Papal States, the Kingdom of Naples, Sicily, and the Republic of Genoa.
His distinctive contribution was the popularization of the Stations of the Cross (Via Crucis) as a standard parochial devotion. The devotion had existed in Italian Franciscan use since the 15th century, but Leonardo was the figure who, through his preaching, brought it to the parish-level practice of every Italian Catholic. He personally erected the Stations of the Cross in over 572 churches across Italy (including, at Pope Benedict XIV's request, the dramatic Stations in the Colosseum of Rome, completed 1750 — re-establishing the Colosseum as a sacred site after over a millennium of profanation).
He preached the great Jubilee year of 1750 at Rome for Benedict XIV — the most consequential 18th-century Italian preaching event, drawing the urban population of Rome out in vast crowds for the indulgenced Stations at the Colosseum. He died at the Franciscan convent of San Bonaventura al Palatino on November 26, 1751 — exhausted by the preceding two decades of preaching. Canonized 1867.