What was the War of the Ancients
10,000 years before Warcraft I The Highborne's reckless use of magic sent ripples of energy spiraling out from the Well of Eternity and into the Great Dark Beyond. The streaming ripples of energy were felt by terrible alien minds. Sargeras - the Great Enemy of all life, the Destroyer of Worlds - felt the potent ripples and was drawn to their distant point of origin. Spying the primordial world of Azeroth and sensing the limitless energies of the Well of Eternity, Sargeras was consumed by an insatiable hunger. The great dark god of the Nameless Void resolved to destroy the fledgling world and claim its energies as his own.
Sargeras gathered his vast Burning Legion and made his way towards the unsuspecting world of Azeroth. The Legion was comprised of a million screaming demons, all ripped from the far corners of the universe, and the demons hungered for conquest. Sargeras' lieutenants, Archimonde the Defiler and Mannoroth the Destructor, prepared their infernal minions to strike.
Queen Azshara, overwhelmed by the terrible ecstasy of her magic, fell victim to Sargeras' undeniable power and agreed to grant him entrance to her world. Even her Highborne servitors gave themselves over to magic's inevitable corruption and began to worship Sargeras as their god. To show their allegiance to the Legion, the Highborne aided their queen in opening a vast, swirling portal within the depths of the Well of Eternity.
Once all his preparations had been made, Sargeras began his catastrophic invasion of Azeroth. The warrior-demons of the Burning Legion stormed into the world through the Well of Eternity and laid siege to the night elves' sleeping cities. Led by Archimonde and Mannoroth, the Legion swarmed over the lands of Kalimdor, leaving only ash and sorrow in its wake. The demon warlocks called down searing infernals that crashed like hellish meteors into the graceful spires of Kalimdor's temples. A band of burning, bloodletting killers known as the Doomguard marched across Kalimdor's fields, slaughtering everyone in their path. Packs of wild, demonic felhounds ravaged the countryside unopposed. Though the brave Kaldorei warriors rushed to defend their ancient homeland, they were forced to give ground, inch by inch, before the fury of the Legion's onslaught.
It fell to Malfurion Stormrage to find help for his beleaguered people. Stormrage, whose own brother, Illidan, practiced the Highborne's magics, was incensed by the growing corruption amongst the upper class. Convincing Illidan to forsake his dangerous obsession, Malfurion set out to find Cenarius and muster a resistance force. The beautiful young priestess, Tyrande, agreed to accompany the brothers in the name of Elune. Though Malfurion and Illidan shared a love for the idealistic priestess, Tyrande's heart belonged to Malfurion alone. Illidan resented his brother's budding romance with Tyrande, but knew that his heartache was nothing compared to the pain of his magical addiction.