Saint Peter Damian (dā´mēən), Ital. Pietro Damiani, 1007?–1072, Italian reformer, Doctor of the Church, b. Ravenna. He became a Camaldolese monk at Fonte-Avellino (near Gubbio) and because of his rigor and asceticism was made prior. He was a strong advocate of church reform and wrote (c.1050) the Liber Gomorrhianus, a scathing denunciation of clerical immorality and homosexuality that created a sensation. In 1057 Stephen IX made him a cardinal against his will. Nicholas II sent him as legate to Milan, notorious for simony and clerical concubinage. In 1069 Alexander II sent him as legate to settle the quarrel between Roman Emperor Henry IV and the empress. In the dispute with Berengar of Tours Peter deprecated the application of reason in theology. Feast: Feb. 23.