The Dragonvault, once called the stronghold of Mal'Gazar, was originally a great fortress from which Maligor ruled the realm of Taurech, during the Godstrife Era.
Within these dark walls, the Vorgar Lords plotted the enslavement of all the races of Tarn. Many Fae came into the service of the Vorgar Lords, giving themselves willingly in exchange for dark powers. And others were enslaved against their will. The dark offspring of Vorgar and Fae were the infamous Trollfolk. The Dragons also dwelt there in great number, another dark spawn of the Vorgar.
The world was plunged into chaos and violence, until the Eldrin and the Avalar joined forces and besieged Mal'Gazar at long last. Maligor was slain, and the rest of the Vorgar Lords bound in magical chains, in the deepest pits of the Netherworld. The Trollfolk, and those Fae in service to the Vorgar fled into dark places.
Long years passed, and those dragons which survived multiplied slowly. By the Dominion Era, their numbers had replenished, and many of them returned to Mal'Gazar, hoarding great wealth their. It became known as the Dragonvault thenceforth, and many brave adventurers travelled there, to claim the treasure for themselves. But few returned alive.