DIETWINO. — In the sources THEOD(EWINUS), cardinal. The year of his birth is unknown. He was a monk at Marmoutier and abbot of Gorze; in December 1134 or shortly thereafter he was created by Innocent II cardinal bishop of S. Rufina (Porto and Silva Candida). Innocent II and Eugenius III chose him for important missions in Germany. In 1135 he worked for the reconciliation of the Hohenstaufen with Lothar II and attended the Diet of Bamberg (18 March 1135). He excommunicated Sigibodo and other schismatics (Jaffé-Wattenbach, 7772). Three years later he facilitated the election of the Swabian Conrad III and crowned him king of the Romans at Aachen (13 March 1138). He remained at Conrad’s side as an advisor until 1142.
During this long stay in Germany he consecrated the altar of the “domus hospitalis Pontis Bargiae” (Jaffé-Wattenbach, 7954) and confirmed the privileges of the monastery of Reichenau (Jaffé-Wattenbach, 8084, 9208). He returned to Germany in 1147 bearing a message from Eugenius III to Conrad III and, together with Cardinal Guido of Florence, accompanied Conrad and Louis VII on the Second Crusade (1147–49) as papal legate. He returned in 1149 and died in Rome in 1153.