Dark elf

Dark elves were elves, known as Ssri-tel-quessir in the elven tongue, and were the ancestors of the drow. The two terms were oftentimes used interchangeably, even by elves (Tel-quessir) themselves.

Dark elves had dark brown skin, as opposed to the the ebony skin that drow had, and pale hair. It was believed that some of them may have had black hair instead of white, and no darkvision.

History
Roughly twenty-seven millennia before the raising of the Standing Stone, the Fey creator race opened gates to the Feywild in an effort to undermine the ruling dragon empires. Through these portals, the first elves immigrated to Toril. These primitive green elves worshiped the Faerie gods (not the Seldarine, which were unknown at this time). Although most green elves were content to remain in small scattered tribes, one group known as the Ilythiiri, negotiated a truce with dragonkind and began carving out a small kingdom in the south. The great Ilythiir capital at Atorrnash would remain a shining beacon of elf culture for millennia.

Other dark elven nations would later arise including the realm of Miyeritar, located in what is now the High Moor.

Wendonai was a balor lord who, in was tasked by Lolth to seduce the Sethomiir clan, rulers of the Ilythiiri into her worship and grant them evil magics. He succeeded and was probably the greatest (but by no means the only) influence on the fall of the dark elves.

In, during the Crown Wars, the High Mages of Aryvandaar cast a fell high magic ritual that completely destroyed the dark elven nation of Miyeritar in an event called the Dark Disaster, changing that realm into a large swampy expanse known as the High Moor.

During the Crown Wars, the Ilythiiri made several unsuccessful attempts at conquering Faerûn (although they conquered Southern Faerûn up to Shantel Othreier), and at the time of the Fourth Crown War, they turned to Lloth and the other evil members of the Dark Seldarine, who gave them powerful magic and fiendish allies as a reward for allegiance. The Ilythiiri's worship of dark deities and the use of their power, led the high mages and priests of all the surviving elven nations to gather at the Elven Court, and channel the power of Corellon Larethian to turn the corrupted dark elves into drow ("Dhaeraow" - traitor), and banish them underground. The original intent was to only curse the dark elves guilty of the crimes committed by Ilythiir, but the spell ended up affecting all of them.

In 1374 DR, Khelben "Blackstaff" Arunsun brought together many powerful mages in order to restore the denizens of the lost city of Miyeritaar's High Mages and cleanse part of the High Moor. In order to make the magic permanent, he and the Grand Mage Ualair the Silent sacrificed their lives to restore Rhymanthiin, the Hidden City of Hope.

Later, in 1379 DR, Q'arlynd Melarn cast a High Magic spell that transformed hundreds among the drow followers of Eilistraee into dark elves. Eilistraee intervened during the casting of the spell, but she withdrew shortly after its beginning. The ritual was meant to affect all of the Dark Maiden's faithful, but of her few thousands of followers (which she had as a lesser power), only the above-mentioned number were transformed. Drizzt was not among them, because only followers of the Dark Dancer were affected by the spell. As of the 1490s DR, post Second Sundering, the returned goddess Eilistraee was still drow, and so were most of her followers.