Witches are assumed to be servants of the devil and in this respect differ from sorcerers, wizards, warlocks, conjurors, and other practitioners of black magic, who have supposedly learned to master the devil.
Witchcraft is worldwide in scope but has had greatly varying roles at different times and places.
From what is known of the Sabbat and from other evidence, most contemporary scholars have come to the conclusion that withcraft was the survival of an ancient folk religion, essentially a fertility cult, that prevailed throughout Europe before the advent of Christianity. According to this theory, the old religion continued to exist alongside Christianity through medieval times, although constantly losing adherents and importance. As Christianity gained the ascendancy, it persuaded most people to regard the gods of the old religion as devils. Those who continued to practice the old religion became witches in the eyes of ecclesiastical authorities and orthodox Christians. The first major witch-hunt in the modern sense occurred in ad 367 by order of the Roman emperor Valerian.