Francesco Faà di Bruno (1825 - 1888) Italian mathematician and saint, best known for the Faà di Bruno formula. He was a captain in an Italian militia, but gave up the post to become a Catholic priest. Instead of saying Mass, however, Bruno dedicated himself to teaching and studying mathematics, publishing dozens of articles in important mathematical journals of the day. He began what would have been a multi-volume book about elliptic functions but did not complete the work.

Bibliography

P. H. Linehan, "Francesco Faa di Bruno" in The Catholic Encyclopedia 1909. New York: Robert Appleton Company