Those who forget the past are doomed to repeat it. Those who remember the past are doomed to watch helplessly as those who forget the past repeat it.
Once marvels undreamt of were common place. Great masses of the noble races (Elves, Humans, Dwarves, etc) mingled in an empire that covered the surface of world. No one remembers what the world was called then. Seemingly in an instant, this world was destroyed. The magic went bad and society crumbled. After the deaths of the powerful wielders of magic, the plagues began. Those who knew the magic or the science to fix the machines, to heal the sick, to store the food were dead.
On these weakened and decimated fragments, the Fell races swarmed. Orcs, Kobolds, and other beings who had been held back took this chance to strike at their long hated foes. Perhaps a tenth of the original populations survived. Now confined to villages, or perhaps a small town, the Noble races eke out an existence, banding together for mutual defense and communal good.
Magic seems to work, but fears die hard. Who knows when the Mawarui will strike again? Wizards are valued for their abilities, but everyone worries that he will be corrupted and take everyone with them. The Clerics are honored, for who would slight the gods? Still, the gods did not save their clerics those many centuries ago.
Welcome to Mawarui.