The Long Watch of Hyjal

The night elves who escaped the Sundering gathered on Mount Hyjal. There they discovered that Illidan had carried vials of the old Well's water and poured some into a mountain lake, creating a new Well of Eternity. Fearing it would one day call the Legion back, Malfurion and Cenarius imprisoned Illidan in the Barrow Deeps, a prison beneath the earth where the warden Maiev Shadowsong would keep watch over him for ten thousand years.

Three Aspects, Alexstrasza, Ysera and Nozdormu, answered by growing Nordrassil, the World Tree, over the new Well. Its roots sealed the waters, and its blessing gave the night elves immortality and the druids a bond with the Emerald Dream, where many of them slept for centuries at a time. Tyrande led the Sisterhood of Elune and the Sentinels, who guarded the forests while the druids dreamed. Arcane magic was banned among the kaldorei.

Not every Highborne obeyed. Some were exiled across the sea and founded Quel'Thalas; others, the Shen'dralar, hid in the city of Eldre'Thalas in what is now Feralas. Its ruins are known today as Dire Maul.