1E 2953. The reign of Emperor Reman I. The Imperial College was becoming weak. Many thousands of years of secrets were lost during the War of Righteousness, and the College never recovered fully from that. One day, a strange visitor appears at their headquarters (Now the Arcane University). He told of secrets he had learned through travelling through Oblivion. His name was Avrel. Those familiar with history may recognize him as Avrel the Black, one of Mannimarco's right hand men, and Lord Avrel, the mighty lich slain by Eleidon. But this took place centuries before the founding of the Order of the Black Worm, and as such Avrel was merely an obscure master of Conjuration.
He proposed opening a portal into Apocrypha, the realm of Hermaeus Mora, so that the College could take the forbidden lore in that library. Many deemed it too risky, but Avrel dismissed their claims, saying that the only risk in Apocrypha was losing yourself in search of endless knowledge, and with enough willpower it could easily be avoided. After weeks of persuasion he had the High Council agree to open a portal. He supplied plans for the ritual, which was to be performed by the most powerful mages in the College.
The ritual at first appeared to be a success. The sorcerers succeeded in opening a portal. However, something came out. A strange immense crystal, blackish purple in color. One by one the mages started to die, the crystal draining their life energy. The portal closed itself after a short time, leaving the corpses of the best and brightest of the Imperial College. Avrel had left long before the ritual began. He had made a pact with the Ideal Masters. In exchange for power, the souls of many accomplished wizards. With all of the professors dead, the Imperial College collapsed on itself.
(Inspired by the pvssyr of a random soul in the Soul Cairn: "How could they trick me like this? I was one of Reman's Court Wizards!")