Cistercian monk, crusade preacher, and legate.
A member of the south German Zahringen dynasty, Conrad joined the Cistercian Order in 1199. He rose to become abbot (in turn) of the monasteries of Villers (1208/ 1209-1214), Clairvaux (1214-1217), and Cîteaux (12171219). In 1213 Conrad was appointed to preach the Fifth Crusade (1217-1221) with the abbot of Rommersdorf in the province of Trier. In 1214 he worked with Arnold Amalric, abbot of Cîteaux, to resolve disputes within the Cistercian Order and reform it in preparation for the Fourth Lateran Council (1215). He also cooperated with other notables to persuade Philip II Augustus, king of France, to end the invasion of England mounted by Philip’s son Louis (later Louis VIII), which threatened the peace essential for the Fifth Crusade.
Made cardinal of Porto and St. Rufina by Pope Honorius III in 1219, Conrad served as legate for the Albigensian Crusade from 1220 to 1223. While attempting to rally support for Amalric of Montfort and to draw Philip Augustus and Louis into the crusade, Conrad worked with local prelates to reform the church in France and won papal approval for a new antiheretical military order. After Philip Augustus’s death in 1223, Conrad was sent to Germany to hasten the preparation of Emperor Frederick II’s delayed crusade to the Holy Land. His acquaintances among reformers and prelates in France and Germany and within the Cistercian Order provided invaluable assistance, as Conrad sought to balance several crusade projects during both legations. From 1224 to 1226, he collaborated closely with Conrad of Hildesheim and the papal preachers appointed in Germany to organize Frederick II’s crusade; extirpate heresy; forge peace between the kings of England, France, and Germany and warring noblemen; and reform secular and regular churches according to the Fourth Lateran’s mandates through disciplinary actions and local synods. From 1226 until his death in September 1227, he participated in several crusade-planning councils in Italy and helped to broker a peace agreement between Frederick II and the Lombard League, enabling the emperor’s departure on crusade.