The Dwindling

Within Elderwyld, the elves innate magical abilities, combined with knowledge learned from their ancestors, allowed them to build the great tree-city of Silhathen. The elves continued to develop their magical abilities, and soon, a pride and arrogance blossomed in their race. Remembering the tales of their goddess reshaping the land at her whim, the great elven mages twisted their magical abilities beyond their limits and raised a group of islands in the Eternal Sea, which they named the Isles of the Sun and Moon. Their accomplishment, however, came at a cost.
Angered by the arrogance and misuse of magic by the elves, Inaris reached out from beyond the veil of the world and cursed the elves. For each age that they endured, a thousand years of memories would be lost, stricken from their minds and never to be recovered. The curse eventually became known as the Dwindling, and it was from this curse that the three branches of the elves came. The elves that blamed the mages for the curse retreated to the roots of the great trees and there they carved giant caverns and twisting labyrinths, becoming known as the Dark Elves. The elves that supported the mages remained in the great towers of Silhathen, and they took the name High Elves. And, finally, those elves who saw little use in fighting amongst their own kind and passing blame, remained in the tree-cities and took the name Wood Elves.