This study is the only available monograph on St Katherine that traces the history of the origin of the cult across eastern and western Christendom in the Middle Ages, up to around 1300. Given its ambitious scope, the result is pleasing. For the first time we have a synthesis of scholarship in English that makes accessible an eclectic amount of research by theologians, historians, literary scholars, classicists and manuscript specialists in every conceivable modern language. There is no evidence for the saint's historicity; the earliest traces of knowledge of the saint date from the seventh century when St Katherine is mentioned in a Syriac litany originating in all probability from Antioch. By the ninth century there are clear traces of her cult in Constantinople. The oldest known version of her Passio, the account of her death, was in existence in the first half of the ninth century but may go back to as early as around 600. In it St Katherine is presented as a defender of the Christian faith, a passionate and learned defence that leads to her martyrdom. From the Byzantine empire the cult spread to into Egypt (Sinai) in the tenth century, southern Italy by the early eleventh century and from there into western France (in particular Normandy) and England. These stages are discussed in successive chapters, though a precise chronology of the Anglo-French–Norman stage in the early and mid-eleventh century remains elusive. The first set of miracula, miracle stories, dates from late eleventh-century Normandy, where Katherine's intercession was, it seems, particularly efficacious in cases of infertility and cancerous illnesses. An English translation of the integral text, based on Rouen, Bibliothèque municipale ms U. 22, fos 112r–115v is included in appendix C. Other appendices contain more translations and manuscript information. Appendix B has a translation of the three hymns written about St Katherine by Alfanus, archbishop of Salerne (1058–85). A useful list of Greek and Latin manuscripts with the various versions of the saint's Passio can be found in appendix A, while appendix D represents in tabular form an analysis of the saint's occurrence in four Winchester calendars.