GERARDO of CAMBRAI. - Theologian and bishop, born at Liège around 975, died on 14 March 1051. A disciple of Gerbert (Silvester II), he became a cleric of Reims, then chaplain to Henry II, who in 1012 appointed him bishop of Arras and Cambrai.
An active man, he founded monasteries, attended synods, and in 1025 celebrated the Council of Arras (atrebatense), whose acts have remained famous for their clear and extensive exposition, in 28 chapters, of the doctrine concerning hierarchy, the Sacraments, and especially the Eucharist (PL. 142, 1270-1313), which at that time was being denied by a heterodox group imbued with Manichaeism (the first symptoms of Catharism). There also remain some letters by him (PL. 142, 1313-23), in the first of which he deals with excommunication.