So let me get this straight..I did some research and dug up some info. After visisting a couple of sites and reading the original Temple of Elemental Evil module I came up with this.
So, Iggwilv was Graz'zt's wife Iuz was their son. After that Iuz got mixed up with ToEE, Zugttmoy and the "Orb of Golden Death" And then his darling mother wrote a great book on Demon Lords and Queens after she betrayed both her husband and son. Later Iggwilv frees Zugttmoy from some prison and takes control of a Thoerpart which can release Tharzidun from his own prison. Am I correct?
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He-he spelt Demonomicon wrong.