Also known as the Kal'Dorei (Children of the Stars) the Night Elves have ended a long period of seclusion at the end of the Third War, joining the Alliance. The Night Elves are native to the continent of Kalimdor where they have faced many hardships.
In the third war, when the Scourge swept through the land and the Burning Legion returned to wreak havoc and destroy all life on Azeroth the Night Elves had to come out of their secluded forests to protect their lands again the Scourge and the Burning Legion alike. The Night Elves led by Tyrande Whisperwind, were strong fighters and they worshipped the Ancients. The Night Elven armies mostly consisted of warriors, saddled atop ferocious, intimidating warsabers, elite archers and rangers, druids, and the Daughters of Cenarius, the Dryads. The Night Elves fought tooth and nail for their shadowed forests. The War started in the human lands on the Eastern Kingdoms, but laster spread through Kalimdor as well. In the end most of the Eastern Kingdoms was destroyed (the human kingdom of Lordaeron, Dalaran, and the High Elven kingdom of Quel'Thalas) and the Night Elves were forced to join together with the remnants of the humans of Lordaeron led by Lady Jaina Proudmoore, known as the Human Expedition and The Orchish Horde led by Thrall in order to repel the Burning Legion. In the final battle taking place on Mount Hyjal, home to the World Tree Nordrassil and the Well of Eternity, the humans and orcs did everything they could in order to prevent the Burning Legion from eradicating all life however they fell after being swarmed by hordes of restless undead. In the end the Night Elves prevailied and Archimonde was destroyed along with all the demons. But in return from saving the world the Night Elves had to give up their immortality and hence joined the Alliance.