Darkness in the Delimbiyr
The magocracy of Netheril was one of the ancient human empires of Faerûn that lie in what is now the vast magical desert of Anauroch. Netheril was also the home of the most powerful mortal wizard who ever walked on Faerun, Karsus. The Netherese also created powerful artifacts known as mythallars, which allow mundane objects to become magical, dramatically changing the face of the Netheril Empire; better said, they benefited the “haves”, the High Netherese, but not the “have nots”, or low Netherese.
It can be said that the empire of Netheril is the oldest surviving human empire, and as such it’s not surprising that it has passed through several different phases. The First Age was the foundering and settling of the Netheril region by humans, and of their contact with elves who taught them magic. The humans learned much, but ignored the elves’ warnings and continued to dangerous territories that nearly sundered all of Toril in a horrible cataclysm.
Undoubtedly during the the peak of their power, theirs was a time when the Netherese were breaking new ground, both in advances of magical pursuits but also exploration into other planes and even across crystal spheres. It is during this age that Karsus lived, a wizard of immense power that sought to grab the power of the gods. His actions directly destroyed Netheril, an event today which is still known as Karsus’s Folly: an attempt to steal the power of Mystryl, goddess of magic. This failed horribly, and all magic ceased to exist for a time.
Since Netherese cities floated above the surface and were empowered entirely due to magic, when the Weave was torn, magic ceased to exist there was nothing to hold the cities up, or keep its citizens alive. Netheril was almost completely obliterated in one fell swoop, as millions perished, screaming, burning and falling to the earth. The enclave of Thultanthar hurriedly tried to save its citizenry by shunting their entire city through an unstable planar portal and were unheard from for nearly two millenia.
Suffice to say, the few Netherese that were away from their cities, or somehow managed to survive abandoned magic entirely, and quietly set off to make their lives anew.