Arnold of Brescia (ca 1100-1155), exiled twice and finally martyred, takes us into the student world of Paris during the blossoming of the twelfth-century Renaissance, through an infamous heresy trial, to teaching in Paris, then Zurich, and into Rome where he was the spiritual leader of the city for almost a decade. Arnold believed the church should be separate from civil government. He supported the revived Roman Senate and the Roman people who were foremost among the many who loved and admired him. An Augustinian canon regular, Arnold made the authorities, ecclesiastical and imperial, tremble. He was a brilliant scholar of Latin literature and Scripture—a combination that made him both sane and formidable. He was first a student and later a colleague of the great Peter Abelard—a champion of reason. Their independence brought them into conflict with Bernard of Clairvaux, relentless defender of the status quo in society and theology. Arnold vigorously supported the democratic commune movement as cities struggled for independence from episcopal control during the twelfth century. A man of learning and action, he challenged the medieval synthesis by which popes and emperors exercised authority.