Demagog, born Brescia, Italy, c.1100;died Rome, Italy, 1155. He became a priest, headed a movement in Brescia to abolish the temporal possessions of the Church as sinful, and was condemned by Innocent II at the Lateran Council (1139). In Paris his propagation of his former ideas caused the Abbot of Clairvaux to have Louis VII exile him. In 1145 he made a solemn abjuration before Pope Eugenius III, but a few months later he attacked the temporal power of the pope and headed a revolution which forced Eugenius out of Rome for three years. Under Adrian IV, Arnold was tried before the Curia, degraded, and probably put to death by the secular power in Rome.