Netheril

While the most known calendar of the realms is Dale Reckoning, there exists a far older measure of achievement, at least by humans: the Neth. A group of small farming villages that banded together for protection led to an empire of human wizards, cities that floated across the sky and a terrible, terrible arrogance that nearly stripped Toril of its magic forever.

The First Age
At the time, Anauroch was a paradise of rivers, forests, lakes and plains. Netheril was unsuprisingly little more than a group of villages (Fenwick, Gers, Gilan, Gustaf, Moran, Nauseef and Janick) along one such lake. Soon after this alliance was named Netheril (after Nether the Elder who is assumed to be the leader) the nation proceeded to remove the threats close by. Seeking to widen its scope of both power and land it began expanding. This eventually lead the Eaerlanni elves to approach the humans. The elves taught the humans of this new alliance magic, and with talent unseen before (possibly because of the shorter human life span) the humans learned arcane spells with a fervor. Every denizen of Netheril was taught the very basic of spellcasting. Even average maids knew cantrips to make the broom sweep the floor. Those who excelled at the arts of magic became known as Arcanists, a rapidly rising political faction that was second only to the nobility of the nation.

The Fall
While the Netheril's flying cities flourished in the sky, magical residue seeped below the earth and became an affliction for a race of subterannean dwelling creatures called the Phaerimm. Eventually, the Phaerimm grew tired of their torment and began to retaliate. They casted spells that drained life and magic from the earth and floating cities of the Netheril, creating barren wastelands where there once were lush fields and areas of Wild Magic. As magic began to keep going uncontrollably awry, many of the Netherese arch mages fled in search of lands where their magic would not go wrong, including Ioulaum, the wizard who first discovered the Mythallar and made the first floating city. The disappearance of the arch mages caused panic, and people began to flee the land.

In an attempt to save his own floating city, or enclave, a young wizard prodigy named Karsus decided to cast a spell he had been researching for decades. In casting the spell, Karsus created a link between himself and the goddess of magic, Mystryl, and stole her divinity and power. At that very moment Karsus swelled with incredible knowledge of everything, including his mistake. The war between the Phaerimm and the Netherese was constantly damaging the Weave, which Mystryl was the only one capable of constantly repairing. To stop Karsus from completely destroying the Weave, Mystryl severed her connection with Karsus, in the process, destroying herself. In the backlash from being disconnected from Mystryl, Karsus was permanently petrified and all magic around the world temperarily went null, causing the Netherese floating cities to plummet into the newly forming Anauroch Desert. Almost immediately after Mystryl died, she was reincarnated as Mystra, the current goddess of magic. Fortunately, she was able to save three of the falling Netherese cities, Anauria, Asram, and Hlondath. Two other cities, the City of Shade (still in existance) and Selûnarra, were saved by Shar and Selûne respectively.

Almost all the surviving Netherese completely forsaked magic. The three cities saved by Mystra were either later destroyed or abandonned.

The Reemergance of the Shade Enclave
When the City of Shade, or the Shade Enclave, began to plummet as the world's magic was temporarily disrupted, it was saved by Shar and pulled into the Shadow Plane for a long time, but returned to the Prime Material Plane in the year 1372DY. They now live on the north-western side of the Shadow Sea in the Anauroch Desert where they rule the Empire of Shadows. The inhabitants of the City of Shade often torture any Netherese that might be surviving in the area purely for the chance to glean information from them, but otherwise consider any Netherese weak.