Age of Darkness
The starfall at the end of the Lost Age spread fire and darkness across the world until only scattered bands of hardy survivors remained. For hundreds of years, these survivors eeked out a primitive existence in a blasted land of ash and perpetual night. The humans sought refuge in the corners of the world farthest away from the starfall, dwarves dug deep into their mountain homes, and the elves clung to the remnants of dying forests. Millions perished, and most of the accumulated knowledge of previous eons was lost.
In time, civilization reasserted itself in the Age of Renewal.