Died 1088; cardinal since 1057. He was (perhaps) a native of Trier, and became a Benedictine. He opposed successfully the heresy of Berengarius, defended the measures of Gregory VII, and composed several theological and scientific works, lives of saints, etc. He is the author of the earliest medieval treatise on letter-writing (De dictamine). Many of his letters are to be seen in the works of St. Peter Damian (P.L., CXLV, 621-634).
Ziegelbauere, Hist. Litt. O.S.B., III, 94; Hurter, Nomenclator (Innsbruck, 1903), V, 1051-52; Wattenbach, Deutschlands Geschichtsquellen (6th ed.), II, 293; Rockinger, Briefsteller und Formelbucher des XI. bis XIV. Jahrhunderts, 29-46.