This study has examined the way in which the Reformation and Counter Reformation influenced key texts in the literature of witchcraft in Early Modern Europe. Certain authors' work has been examined in detail: Pedro Ciruelo, Martin of Arles, Symphorien Champier, Gianfrancesco Ponzinibio, Nicolas Remi, Henri Boguet, Francesco Maria Guazzo, Niels Hemmingsen, Lambert Daneau, George Gifford, James VI and Reginald Scot. These writers include both those who were extremely sceptical, and also those who were very credulous about the abilities of witches. These are not the only demonologists referred to, however, as each work is put into context. The beliefs of the Church Fathers and the Scholastics are also examined; this means that the beliefs of the later writers can be put into perspective, and examined to see where, if at all, they are diverging from accepted Church doctrine. The study examines the individual elements of witch belief, including the sabbat, flight, magic, superstition, maleficium, and incubi and succubi. The demonologies changed dramatically from 1450 to 1610, and this was partly due to the influence of the reformations. In particular, the Roman Catholic position changed, as the Counter Reformation Catholic writers were forced to deny earlier beliefs in order to differentiate their position from that of the Protestants. The pre-Reformation and Protestant writers tended to focus upon the more common manifestations of the devil's power, such as superstition; while the Counter Reformation Catholics were interested in the more sensational elements, such as flight and the sabbat. This means that although they are of different confessions, the pre-Reformation writers and the Protestants have more in common than the two groups of Catholics.