The World Tree
Teldrassil (meaning "Crown of the Earth" in Darnassian) was a World Tree situated on the eponymous island off Kalimdor's northwestern coast. Created shortly after the Third War by the night elves, Teldrassil served as their home and primary base of operations, its thick crown housing the capital city of Darnassus. Other major settlements on the tree included Rut'theran Village, Dolanaar and Shadowglen. Owing to its size, Teldrassil possessed its own unique ecosystem with a various flora, fauna, and vast twilit forests.
The new tree was not blessed by the Dragon Aspects at its birth, unlike its predecessor Nordrassil, which would ultimately leave it vulnerable to corruption from the Emerald Nightmare. However, just before the Cataclysm, it would receive the blessings of Alexstrasza and Ysera. All known lingering corruption was finally purged during the Cataclysm.
Teldrassil served as the largest bastion of Alliance power in Kalimdor, and maintained naval connections to the mainland, the nearby Azuremyst Isles, and the distant Eastern Kingdoms. Many young and ambitious night elves began their journey out into the world from the verdant shelter of the World Tree. During the War of the Thorns—roughly a decade after its creation—Teldrassil was burned down by the Horde under the orders of Warchief Sylvanas Windrunner, killing many of the night elves dwelling in it.
After the cataclysmic events of the second invasion of the Burning Legion, Malfurion Stormrage became trapped in the Emerald Dream. In Malfurion's absence, Archdruid Fandral Staghelm took over leadership of the night elven druids, and convinced the Circle of the Ancients in Darkshore that it was time for the night elves to create a new World Tree and regain their immortality.
The Circle of the Ancients and the wise druids led by Fandral combined their powers to grow an immense tree in the Veiled Sea. They called the tree Teldrassil, meaning "crown of the earth" in Darnassian. The night elves made their new home of Darnassus in the boughs of Teldrassil, creating a forest of mighty trees and flowing rivers, bathed in the endless night that fell over the lands of the elves from the dawn of time. However, the tree did not restore the night elves' immortality; Nozdormu, whose blessing on Nordrassil had been the source of their immortality, saw the night elves' wish as arrogant and refused to bless Teldrassil.
Over time, the land atop Teldrassil fell into the shadow of a sinister presence. Local creatures such as furbolgs and grell went mad, and satyrs appeared, intent on further corrupting the land. Giant turtles and threshers known to inhabit the waters surrounding Teldrassil began fleeing the tree to beach themselves and die on Darkshore. The source of this corruption remained a mystery for some time, until the conflict of the Emerald Nightmare spilled into the waking world.
During the Scourge Invasion, Teldrassil was attacked by the Scourge.
After Malfurion was freed from the Emerald Nightmare, he flew to Darnassus, and discovered that a remnant of a great evil had been grafted into Teldrassil by Fandral. By grafting Xavius' fel-tainted branch into Teldrassil, Fandral had given Xavius, as well as the evil behind his transformation into the Nightmare Lord, a tie to both Azeroth and the Emerald Dream.
Malfurion managed to remove the corrupt branch and eventually restore the tree to a state closer to what it originally should have been. Alexstrasza, impressed that the tree could prosper alone without her influence or her kin's, blessed it belatedly. She later blessed it again, along with Ysera this time, during the wedding of Malfurion and Tyrande Whisperwind--a blessing which protected Teldrassil to its final day. The tree flourished even more under the gifts from the Life-Binder and the Dreamer, though it still cannot return the night elves' immortality without a blessing from Nozdormu.
- See main article: Cataclysm
Around the time of the Cataclysm, the worgen arrived to the cleansed Teldrassil. When Malfurion Stormrage checked the heart of the World Tree, there was no apparent corruption. The archdruid however, remained vigilant as he knew that pockets of the taint remained in the Emerald Dream, so Teldrassil was still vulnerable.
Some time later, Teldrassil's recovery slowed, and signs of the Nightmare's corruption resurfaced. Though already burdened by political tension and the vast destruction unleashed by the Cataclysm, the night elves worked to find the cause of their World Tree's ailment. They discovered that this was no new corruption, but lingering remnants of the original corruption, being pushed out by Teldrassil itself. With the corruption having been buried deep within Teldrassil, it would have been impossible to strike at the source without killing the world tree itself, but the Aspects' blessing allowed Teldrassil to force the taint to the surface in a form that the night elves could destroy. The Bough of Corruption was the one last remnant of Xavius on Teldrassil, and was the source of the Fel Moss that tainted the gnarlpine, the timberlings, and other creatures.
War of the Thorns
- See main article: War of the Thorns
Teldrassil was burned down by the Horde under the orders of Sylvanas Windrunner. It was the largest fire Azeroth had ever seen. Many survivors escaped to Stormwind City via portals, where they settled in the area around Olivia's Pond, with injured refugees in the Cathedral of Light and Stormwind Harbor and other small groups scattered throughout the city. Other survivors sailed to the beaches east of the besieged Lor'danel. From there, preparations were made to evacuate them to Azuremyst Isle while other night elves stayed in Darkshore to continue fighting the Horde.
Adapted from Wowpeida