The idea that paganism survived in medieval and early modern Russia alongside orthodoxy is widely held in Russia. This book explores the accuracy of this view, demonstrating that 'double belief', dvoeverie, is in fact an academic myth - a myth which arose with nineteenth century scholars obsessed with the Russian 'folk' and their special characteristics, and which was perpetuated as a propaganda tool in the Soviet period. It shows how the concept of dvoeverie has coloured our perception of both popular faith in Russian and medieval Russian culture for over a century, and how scholars, citing the medieval origins of the term, have often portrayed Russian Christianity as uniquely muddied by paganism, with 'double-believing' Christians consciously or unconsciously preserving pagan traditions even into the twentieth century. It surveys the wide variety of uses of the term from the eleventh to the seventeenth century, and contrasts them to its use in modern historiography, concluding that our modern interpretation of dvoeverie would not have been recognised by medieval clerics, and that 'double-belief' is a modern academic construct. Furthermore, it offers a brief foray into medieval Orthodoxy via the mind of the believer, through the language and literature of the period. If clerics didn't use the word dvoeverie to identify acts as unorthodox, which words did they use, and what can these words tell us about popular faith? Was the populace of Rus really more resistant to Christianization then their European counterparts? What was it about popular culture that alarmed the clergy of medieval Rus, and were their concerns so very different from those of Western European clergy, or the clergy of other neophyte peoples?.