jats:titleAbstract</jats:title> jats:pTaking as its starting point the well-known English effort to ‘convert’ Venice to Protestantism in the wake of the Venetian Interdict controversy (1606–7), this article explores the ways in which early modern conceptions of conversion varied according to context. Drawing on evidence relating to Venice, England, Ireland and the Jesuit missions to China, it traces how divergent understandings of religious change shaped – and were shaped by – confessional controversy. The idea of ‘conversion’ posed particular conceptual difficulties as a description of inter-confessional transfer, and this article probes the implications of these difficulties for religious and political debate.</jats:p>