In Rome, where strategies to re-establish Roman Catholic orthodoxy were formulated, the problem of how to deal with foreigners and particularly with ‘heretics’ coming from Northern Europe was an important priority throughout the early modern period. Converting foreigners had a special significance for the Papacy. This volume, which includes several case studies, explores the meaning of conversion and the changes of policy adopted by the church bodies set up to protect orthodoxy. It uses inquisitorial documents (from Archivio della Congregazione per la dottrina della Fede) and sources from other archives and libraries, both in Rome and elsewhere. This book is an updated and revised translation of Convertire lo straniero (Viella, 2011), including a bibliography reflecting the most recent scholarship on its subject.