A long time ago, so long that the elves only have a vague sense of recollection when it is whispered among the elders of the world, the lands of Caederon had been ruled by a central monarch. His lands were at peace and his people loved him. The balance between divine and arcane was perfect. Naturally, he had evils within his lands. As did the divine and arcane sects. However, this concerned him not. He knew the key to peace was balance.
Deep within the labyrinth of caverns beneath the Arcane Sanctum of High Sorcerery, the conjuerers of a darker college of the arcane despised this long-settled peace. Their enmity was even palpable. Like a black ocean, it poisioned the country and rippled through the planes. But being humans with an altogether duller perception, the people never sensed this. Others did and heir hatred did not go unheeded.
Thus, one night, a man came to these dark mages. And this same night, he went to the dark mystics in churches throughout Caederon. He told them his name was the Serpent. He came as a messenger from his god, the Maimed Lord, Vecna. He gave them the Knowledge and Magic of Death that is prized so highly among the followers of Vecna. This, as the mages knew, would easily upset the balance that was so revered in the lands of Caederon. And thus, the dark mystics and mages, armed with the secrets of Vecna, killed all who opposed them. The other mages and priests were purged from the world. Not all of them. Only those who refused to submit to the will of The Archmage. To the Serpent. To Vecna.
The strongest mage among them took upon himself to rule the lands of Caederon. He became known as The Archmage. He divided up the lands of Caederon into provinces. Each of these would be given to his most loyal and powerful vassals. Noone knows how many centuries have passed since then. However, the Archmage has never left his post. He was never been succeeded. Unlike his subjects underneath him, who changed their rulership constantly, he was and is still now in command of Caederon. His sect of dark mages, those blessed by Vecna, is the One and the Five.