A god demoted to a demon, and the second name in nearly every hierarchy of Hell. Ba'al Zebub — 'lord of the flies,' most scholars read it as a mocking Hebrew distortion of Ba'al Zebul, 'Baal the Prince' — was the oracle-god of Philistine Ekron, consulted by King Ahaziah in 2 Kings and condemned by the prophet Elijah for it.
By the Gospels he is 'the prince of demons,' the name by which Jesus' opponents describe the power behind his exorcisms. Demonology never lets a title like that go: Binsfeld gives him gluttony among the seven princes; Milton seats him beside Satan as the fallen second-in-command; and the possession records of Loudun in 1634 — the most heavily documented possession case in European history, with royal commissioners taking notes — list Beelzebub among the demons named in the sisters' afflictions.
The archive holds him as the type case of a pattern that recurs across this collection: yesterday's neighbor-god becoming tomorrow's devil. The flies, at least, everyone agrees on.