Ioulaum is perhaps best known as the man who created the Mythallar, the
device that allowed the empire of Netheril to build their flying cities
roughly 5,000 years ago. What isn't as well documented is that just before
the fall of the Netherese empire roughly 1,600 years ago, Ioulaum was
forced to turen himself into a Lich and send himself into the future,
hoping the weave would be more stable.
He found himself in present day, with a much more stable - and much less
powerful weave. His researchings began to leave him disappointed as he
found the weave had been altered severely, but he also found the existance
of another source of magic, guarded by the Mistress of Night, Shar.
His delvings into this dark source of magic, as well as the inevitable
effects Lichdom was having on his humanity, began to warp his mind towards
the Lady of Loss, and he was soon cast out by Mystra, and declared an
enemy of the church.