Nochtiatus (Dark Elves / Drow)
Despised by all the “good” races, especially other non-Drow Elves, the Drow were not always “evil”.
They once had a completely different socio-political structure, and worshiped very different deities.
They have a complex history that most no longer remember (including many of the Drow).
Though most drow elves now are under pressure to take acts that others consider “evil”, there are the rare few that rebel against the teachings of Lolth and the priestesses.
Usually just a few rare individuals, these "rebel drow", over time they find each other and slowly begin to cluster in hidden underground towns, or above ground.
Unfortunately, these rarely lasts more than a few decades before Lolth finds out and orders the complete annihilation of their kind, because Lolth finds out and orders their complete annihilation.
Some Drow take the chance of going abroad among other races.
Unfortunately most of the ”good” races will generally attempt to capture and kill a Drow on sight.
The surface Elves are in denial. Especially the Wood Elves.
They think the Drow are actually a propaganda effort by humans to discredit elves in general, and an excuse to attack elves as a whole.
The high elves do remember the Drow, and are not in the denial of some of the wood elf tribes (it helps they keep details copious written archives spanning thousands of years), but they speak about it only in very hushed whispers with only those they trust most.
Preferring to bury the “black sheep” branch of their people and try to forget the tragedies caused by those that were once their closest kin.
Humans have such short lives and shorter memories, they think Drow are just fairy tales made up by parents to scare little children into submission.
Many of the "darker" (underground dwelling) races occasionally will see, and even work with a single or small group of drow, but few have ever been allowed to know about what are now considered the "true stories" of the dark elves (but which actually buries their original past), except the partner races such as driders, dwarrows, etc, that live in, or near, the great underground cities steadily growing.
Centuries ago the Drow wiped out the Sea Elves' mighty underwater kingdoms.
Though great kingdoms, the very nature of underwater life, the Sea Elves had little in way of war culture, so were easily crushed by the Drow and their allies.
Then the Drow began assaults on the separate wood elf lands. They overreached however, when they attempted to take on the High Elf kingdoms.
After decades of the Drow growing in their power unchallenged, the growth came quickly to a halt.
The high elves and the others turned the tide quickly.
Steadily the Drow were forced from land after land, though as they were pushed back they did not leave gracefully, salting the lands and destroying all they left behind.
The worst of the battle happened in the northern lands. The Drow had their backs to the great ice (much smaller then), they unleashed most of their dragons to fight the other's great forces. The unleashing of such powers had a cataclysmic effect. Earthquakes, Volcanoes erupted, new mountains shot up, others toppled, seas came crashing in, and new islands were formed, the lands were torn asunder.
During the chaos, the Drow used special portals to escape deep underground, and to the far north, deep under the ice. Under all of the dust, and smoke, and chaos, most people now believe all the Drow were slain.
Only in the past decade have rumors of the Drow transformed from just “old wives tales” to frighten children into compliance, and into actual sightings of individual Drow here and there. But no more than that.