Over the past forty years, major Patristic scholars have radically called into question the biographical and literary profiles of Gregory Thaumaturgus (the ‘Wonderworker’), considered for centuries the famous pupil of Origen and the charismatic bishop of Neocaesarea. Presenting a thorough reconsideration of the ancient sources on Gregory and the main works ascribed to him, Preaching the Gospel to the Hellenes demonstrates that the doubt cast on his traditional figure is unwarranted. The book re-establishes solid ground on which this important actor in Early Christianity can be placed and corroborates his engagement in confronting and evangelising pagans. Moreover, by taking a fresh look at information provided on Gregory by key Patristic authors and scrutinising the addressees of his works, this study sheds new light on the Christian cultural and social environment in Palestine and Asia Minor, as well as on the history of Christian theology between the third and fourth centuries.