The Arthonean Cleansing
Commonly referred to as "The Day the Sky Fell", The Arthonean Cleansing was a worldwide apocalyptic meteor shower that directly or indirectly killed the majority of life on Arthos. It is estimated that Arthos suffered 18 major impacts to its surface and a countless number of minor impacts that have since become undetectable due to crater erosion.
Despite the moniker, the meteor shower happened in the space of multiple days. As the first meteors entered Arthos' atmosphere, the sky ignited with embers and wildfires ravaged the landscape. Anyone caught near an impact was either killed instantly or died soon after from asphyxiation. Population centers devolved into total chaos and many perished in the pandemonium. Those who survived were either in tiny communities far from the nearest impact, or fled underground. It is believed that some dwarven cities benevolently took in refugees whereas most turned non-dwarves away. Dwarf historians contest that it was the other way around and that the other races could not have survived without their altruism.
The Long Still
For 2 years, Arthos remained a barren husk. Those clinging to life on the surface had to make due with a fraction of the sunlight needed to grow crops. The ashen haze now blotting out the sky drove many to madness. The subterranean cities were strained to their breaking point from having to feed the massive influx of refugees. Starvation was a fact of life. The combined world population of the Prefellian races could not have exceeded 80,000 by the time The Source crashed into the Fairdonnel Ocean.
Virtually no records of culture dating before the cleansing survive. Very little could be done in the way of preservation as the immediate aftereffects of the meteors did not spare those weighed down by personal belongings. The artifacts fashioned from stone were able to survive the elements but were soon found and destroyed during The Age of Revival. Historians believe this was the result of an iconoclastic movement to repent for the sins of the past and ensure the gods would not allow a cleansing to occur in the future. Both historians and religious institutions now regard this as a mistake.