What is "cyprianus"

Cyprianus is a name given in Scandinavian traditions of folk magic to the "black book" ("Svarteboken"): a grimoire or manuscript collection of spells; and by extension to the magical tradition that these spells form a part of. There is no standard text called "Cyprianus"; it was a general label given to a collection of spells.

Manuscripts called or referring to Cyprianus had a dark reputation; in some versions, you obtained the text by renouncing your baptism and devoting yourself to Satan. The common people's opinion of the book was that it was a standard grimoire concerned with the summoning of demons and spirits. Ministers were often thought to have obtained it through their studies at university; it is not coincidence that ministers' wives often functioned as folk healers in rural communities. Like many such texts, it is bound to its owner and hard to get rid of; it will not burn nor be destroyed by water, and attempting to discard it will only result in its supernatural return. These compilations nevertheless were widely circulated among the cunning folk of Scandinavia, who in a rural land with few physicians were the folk healers sought out by ordinary people beset by injury or illness.