History of Cumulus City

Legend claims that during some now forgotten conflict between deities in the first era, the asteroid known as Cumulus Hills was grabbed from the heavens and placed in the near orbit of Valmars. The motivation or even the responsible party are topics of frequent speculation, but no evidence exists to confirm or deny any of these theories.
The first official mention of Cumulus Hills is in a history book written in the 3rd era by famed Aasimar historian Arken Valtira. Her writing style, while dry, is extremely detailed. Her multi-volume anthology chronicles much of the early history of the region, starting with it's official founding as ""neutral territory"" at the end of the Great Empyrean Wars. The founding of Cumulus City is often regarded as the start of the third era to many Empyrean scholars. Since then, the city has remained without conflict, as have the signatories of the Empyrean Alliance (Arakocra, Aasimar, Dragonborn, and Goliath).
The third era saw exponential growth. Thanks to increased trade with the surface civilizations of Valmars, Cumulus City grew immensely in both population and economy. It managed to avoid much of the conflict on the surface and prospered when the surface world was overcome with centuries long war.
During the fourth era, the surface world finally reached an uneasy peace. More arcane advances in Cumulus City led to trade routes opening with Sigil, the City of Brass, and other Planar locations.