Born to the Italian nobility. He studied theology at the Benedictine Monastery of Saint Perpetuus at Asti, Italy, and at Bologna, Italy. He was ordained in 1079, and assigned to a parish at Siena, Italy. Noted for defending orthodox Church wisdom, for his knowledge of Scripture, and for his teachings on the Blessed Sacrament. He has been a counselor to four popes. Ordained bishop of Segni, Italy in 1080 by Pope Gregory VII.
Fought simony and lay investiture. In 1095 he retired to a monastic life at Monte Cassino. Elected abbot in 1107. Following a chastisement of the pope for shirking his duty to others, he was soon ordered back to his diocese, a vocation he fulfilled until his death. He also became a Vatican librarian. Cardinal legate, though he declined the cardinalate. And a notable author of several works on theology.
