Medical condition, demon or undead corpse? Sleep paralysis and the nightmare in medieval Europe

The aim of this article is to analyse the popular perception of the nightmare in medieval Europe. The first section will explore the ways in which the base experience of the nightmare (as documented in neuropsychological research) was interpreted according to Church doctrine, classical dream theories and Galenic medicine. Then, with reference to the remedies used to protect the body against the mara found in Anglo-Saxon medical manuals and the tales of demonic/ghostly assault from twelfth-century Anglo-Norman literature, it will be seen how the authoritative interpretations of the nocturnal assault were replicated, rejected or interpolated in the rhythms of daily life. Ultimately, this article will argue that the nightmare experience can be read as an independent ‘text’; a universal function of the human body that is given substance and coherence depending on the habits, experiences and fears of the percipient