Theophilus was born in Corsica of rich and noble parents. As a young man he entered the Franciscans and soon showed his love for solitude and prayer. After admirably completing his studies, he was ordained and assigned to a retreat house near Subiaco. Inspired by the austere life of the Franciscans there, he founded other such houses in Corsica and Tuscany. Over the years, he became famous for his preaching as well as his missionary efforts.
Though he was always somewhat sickly, Theophilus generously served the needs of God's people in the confessional, in the sickroom and at the graveside. Worn out by his labors, he died on June 17, 1740. He was canonized in 1930.