Beelzebub (also Baal-zebub, Baalzebub, and Beelzebul) was an epithet given to Baal, the chief god in the Canaanite pantheon. Originally known as "Baal, the prince", Beelzebub was demonized after contact with monotheistic Judaism, and he became known to them as the Lord of the Flies (see also Baal, Beelzebub and the New Testament in Baal). In contemporary Christianity, Beelzebub has simply become an alternative name for Satan or the Devil.
In the Old Testament, when King Ahaziah of Israel fell ill, he sent messengers to call upon Baal-zebub (Beelzebub) for a prognosis and was rebuked by the prophet Elijah for doing so. (2 Kings 1:2-3.) This was the only appearance of Beelzebub's name in the Old Testament. However, Beelzebub's name reappeared in the New Testament when the Pharisees accused Jesus of casting out demons in Beelzebub's name (Matthew 12:24); he is also mentioned in Matthew 10:25, and Mark 3:22 and Luke 11:18-19, being called "prince of demons" in Matthew and Mark, and openly compared with Satan in Luke.
All demonological accounts of Beelzebub place him high in Hell's hierarchy. A book presumably written by Faust in 1505 placed Beelzebub among the five most powerful demons in Hell, the other four being Lucifer, Satan, Astaroth, and Beherit, and according to the renowned 16th century occultist Johannes Wierus, Beelzebub is the chief lieutenant of Lucifer, the emperor of Hell, and presides over the Order of the Fly. Similarly, the 17th century Father Sebastian Michaelis placed Beelzebub among the three most prominent fallen angels, the other two being Lucifer and Leviathan, whereas two 18th century works identified an unholy trinity consisting of Beelzebub, Lucifer, and Astaroth. However, John Milton featured Beelzebub as merely being one of the many fallen cherubim in the epic poem Paradise Lost, first published in 1667.
Father Michaelis associated Beelzebub with the deadly sin of pride. However, according to Peter Binsfeld, Beelzebub was the demon of gluttony, one of the other seven deadly sins, whereas Francis Barrett asserted that Beelzebub was the prince of false gods. In any event, Beelzebub has been frequently named as an object of supplication by confessed witches. After being accused by the Pharisees of possessing Jesus, he has also been held responsible for at least one famous case of alleged demon possession which occurred in Aix-en-Provence in 1611 involving a nun by the name of Sister Madeleine de Demandolx de la Palud who named one Father Jean-Baptiste Gaufridi as a bewitcher of young nuns.