My research examines demonic copulation in early modern Zürich. These supposed sexual encounters between alleged witches and demons served as the primary evidence through which the otherwise ephemeral crime of witchcraft would be conceptualised and ultimately proven in court. My project seeks to determine if responses to these sexual interactions changed throughout the period of witchcraft persecution in Zürich, and the ways in which various understandings impacted the trial process itself. This research considers a range of perspectives including those of theologians, parish clergy, local political authorities, medical practitioners, urban guildsmen, and rural townsfolk to reconstruct a multilayered image of belief encompassing the wider Zürich community. The Herzog August Bibliothek contains one of the richest collections of witchcraft treatises in the world and will enable my research to trace the demonological perspectives of the political and theological elite.