The Scholomance was a legendary school of black magic in Transylvania. It was said to be run by the devil himself. An extract from Emily Gerard’s article ‘Transylvanian Superstitions’ describes the Scholomance:
As I am on the subject of thunderstorms, I may as well here mention the Scholomance, or school supposed to exist somewhere in the heart of the mountains, and where all the secrets of nature, the language of animals, and all imaginable magic spells and charms are taught by the devil in person. Only ten scholars are admitted at a time, and when the course of learning has expired and nine of them are released to return to their homes, the tenth scholar is detained by the devil as payment, and mounted upon an Ismeju (dragon) he becomes henceforward the devil's aide-de-camp, and assists him in 'making the weather,' that is, in preparing thunderbolts.