Lord Taug is the Chaos Lord whose reign led to the downfall of the once-mighty troll city of Kasmarkin. Emperor Rakmarkha III, known through history as the Mad Emperor of Kasmarkin, learned of the demon lord Taug through his dabblings in the occult and communications with the Unborn Goddess - later discovered to be Eris.
Together, Rakmarkha and Taug planned to use Kasmarkin as a gathering point for the energies of Chaos. Their plan failed when Senator Schlastan and other members of the Senate, as well as the commoner Alcibiades, learned of Taug's true identity and used the knowledge to defeat him. Taug was imprisoned within a crystal by Schlastan. The Mad Emperor and his followers attempted to sacrifice themselves to free Taug but only succeeded in submerging Kasmarkin into the depths of the Mannaseh Swamp in which it was built.
Later, the Necromancer Xerimor visited the sunken ruins to raise Taug on a quest for power. Taug acceded, before sending the necromancer to exact his revenge upon the Danaeus for an ancient betrayal. Xerimor gathered an army summoned to raid the plane, bringing the dark savant to be imprisoned at the feet of Taug. Justice for the kidnapping was swift. Jy'Barrak Golgotha himself ascended from the depths of the Chaos Plane on a mission to retrieve his advisor, tossing Xerimor in the cage at the dark savant's place.
Though periodically released and dominated by adventurers for their own purposes, for centuries Taug was unable to permanently escape his imprisonment. It was not until the outset of the Elemental War that the Chaos Lord was freed in truth by the machinations of the Vigil. Upon his release, he declared his identity to the world once more: Pazuzu, the Demon Prince. The Kx'khrah legions of Lorielan stormed forth from the Crystal Plane to recapture him in rage. The demon lord fled from his would-be captors, opening a transdimensional portal at the Flame of Yggdrasil to escape along Yggdrasil's interplanar branches.