Drow

"In no singular instance have I seen a people so closely mirror their homeland" -Thoros Myn, Grand Archanist of the Tower.
The Drow are a close cousin of their surface brethren: Elves. For millennia the Drow have lived below ground in the vast under-world known simply as the Under-Dark. Here the Drow maintain dominion over their vast network of cavernous cities, and lay in wait for their final vengeance against their hated Elf enemies. The seed of this hatred was born at the dawn of time. When the Pillars of Ourell taught Elfkind the secrets of magic there was one elf who mastered it before any other: Haradin. But in Haradin's hubris he drew the wrath of the gods, and brought ruin upon his people. Haradin was driven out of his home and into the Underdark where he and his followers became the first Drow. 
Today the Drow worship Haradin as Lolth, god of spiders, and hope to avenge his humiliation at the hand of his elvish bretheren.