The study of 'Arianism' has proved one of the abiding fascinations and the abiding problems of early Christian studies in recent years. Here, Vaggione addresses the definition of the doctrine and why it generated such intense social turmoil by examining the standpoint of one of 'Arianism's' principal supporters, Eunomius of Cyzicus. Eunomius' life is used as a framework within which to discuss changes in the doctrine of the Trinity.