At some point more than twenty-five thousand years ago, the champion of the Pantheon, the valiant Titan Sargeras decided his eternal mission of protecting the works of his fellows had no meaning, was without purpose - it was pointless because the entire cosmos was pointless, a sick joke. You couldn't perfect creation. It was a place of seething, formless madness, where primordial evils like the Old Gods and the Nathrezim could arise. All the Titans works were ultimately doomed. In Sargeras' eyes, the Titan experiment had failed, and they should stop trying to make an orderly universe. It would be best if nothing would ever arise.
Since the Titans refused to understand, Sargeras decided he would force the issue - he would destroy creation faster than they could perfect it. He would annihilate all life. So he broke the bonds of the ancient prisons the Titans had created and loosed the very evils he'd once confined, and offered them a choice - destruction now at his hands, or destruction later, after all creation was so destroyed. Seeing that the time scale involved was massive, the Nathrezim and other demons of the Twisting Nether agreed to serve Sargeras. He had an army.
Now all he needed were generals.
So Sargeras came to Argus.
The eredar of Argus were a long lived, magically gifted race, who had seen civilization rise and fall many times, and had secrets even they
didn't fully understand such as the Ata'mal Crystal, a relic so sacred that only the three members of Argus' ruling Triumverate were allowed to access it. It was to these wise and powerful triumvirs, Archimonde, Kil'jaeden and Velen, that Sargeras appeared. He offered them knowledge of the cosmos and power enough to explore it, and understand it. And it must be said - Sargeras kept his bargain.
Both Archimonde and Kil'jaeden recognized the enormous power and intellect of the godlike being before them. Velen, too, realized that if Sargeras were not
a god, that which he was might well be greater
than a god. Yet something in the manner of the visitor concerned him. His own gift of prophecy told him to suspect the offer, and so he went off to meditate, and in so doing he learned the truth. Sargeras would grand the eredar enormous power at the cost of their sanity, their very souls would be warped by the Titan's unrelenting hatred for all existence, and they would come to know the universe as they marched across it. Slaughtering and burning and warping everything their annihilating wake, the extinction of the cosmos made flesh in Sargeras' image. The Dark Titan would keep his promise. The eredar would be powerful and intelligent with knowledge gleaned from Sargeras himself - and they would be utterly vile monsters that killed as easily as breathing.Velen made his escape
thanks to the Ata'mal Crystal and its connection to the Naaru. It's likely Sargeras didn't even notice and likely wouldn't have cared much - he had what he'd come for. The majority of the eredar were now his, serving as the officer corps of his Burning Legion, and in Archimonde and Kil'jaeden he had generals to lead his war host. They proved admirably suited to the task.Archimonde soon recruited the Annihilan, or Pit Lords, to be the shock troops for the Legion - massively powerful both physically and magically, they would be living weapons, capable of laying waste to entire mortal armies.
The Legion rampaged across countless worlds before Sargeras discovered Azeroth, drawn by the power of the Well of Eternity. It's unknown if Sargeras was part of the Titan expedition that shaped Azeroth, created many wonders such as Ulduar and Uldum, and left behind the planetary re-origination devices, but the Well was a source of pure fundamental magical power that could serve as a means for Sargeras to actually walk bodily upon the surface of the world. The War of the Ancients (as we know today) was ultimately brought about by Sargeras and his desire to rampage across Azeroth, and the Dark Titan corrupted Azshara and her Highborne to serve as instruments of his will in the process. (Azshara, at least, seems to have served out of a misguided desire for Sargeras as her mate, seeing in the Dark Titan the only being in creation she felt worthy of her.) Armies of demons were soon flowing through the portal, led by Hakkar the Houndmaster, Mannoroth, and eventually Archimonde himself.
The ultimate end of the War of the Ancients
saw the Well of Eternity disrupted, Sargeras balked on the very cusp of stepping through the portal, and the destruction of the ancient continent of Kalimdor. For the first time in its existence, the Burning Legion knew failure. Sargeras eventually hit upon a new plan, and using an Avatar he managed to infest the powerful Guardian of Tirisfal Aegwynn
, but this was many thousands of years later. During all of that time, the Legion marched on - hunting the former eredar now called draenei from world to world, simultaneously rampaging across creation. Many worlds died for the simple sin of existing
Recent events have proved the Legion remains a threat to all existence - Kil'jaeden's plan for revenge against the draenei who'd fled to Draenor meant the creation of the original Horde and the near extinction of the draenei, while Sargeras' scheme to infest Aegwynn allowed him to possess the body of Medivh, her son, from birth - this would lead to the creation of the Dark Portal and the unleashing of the orcs of Draenor upon Azeroth, and thus, the wars from which the Warcraft setting draws its name. And the Legion's second attack on Azeroth created the Scourge. This is how utterly vile and destructive the Legion is. It created a war host of undead merely as a means to soften Azeroth up for its own
invasion of the world - the dreaded Scourge and the vaunted Lich King are ultimately just tools that managed temporarily to forget their true purpose as expendable weapons. And it's telling that the Lich King only managed to ultimately rebel against the Legion after
Archimonde's costly defeat during the Third War
The Third War was indeed costly for the Legion as well as Azeroth. Archimonde, one of the two field commanders of the Legion entire, fell atop Mount Hyjal, destroyed by the unleashed power Nordrassil had drunk from the Well of Eternity for over ten thousand years. Kil'jaeden, being ultimately a more subtle sort of eredar, found that his pawn and puppet the Lich King (formerly Ner'zhul, the orcish shaman Kil'jaeden had duped back on Draenor) had plans of his own, and so he sought another pawn to deal with this rebellion. Thus Illidan Stormrage found himself working for Kil'jaeden so soon after having seized the ruins of Outland for his own and defeating Magtheridon, Mannoroth's replacement as lord of the Annihilan. Sadly for Illidan (and perhaps Azeroth) he failed to destroy the Lich King and
he failed to prevent Arthas Menethil from becoming one with Ner'zhul, and so, skulked back to Outland to hide from Kil'jaeden's eventual vengeance.
Kil'jaeden, however, had a bigger prize in mind - he would use the blood elf prince Kae'thas Sunstrider (formerly one of Illidan's lieutenants) to open a portal so that Kil'jaeden could enter a weakened Azeroth (still reeling from the Third War and no longer unified, as conflict between the Horde and Alliance had increased) and conquer it himself, cementing his position as the true lord of the Burning Legion. With Sargeras lost in the Nether since the death of Medivh during the First War (he got better) it was a reasonable plan, foiled only through the quick action of a desperate band of heroes. And yet Kil'jaeden, although driven back, still remains in command of the Legion, which still thunders across the cosmos laying waste to all life.
While you don't need to have played the previous
Warcraft games to enjoy
World of Warcraft, a little history goes a long way toward making the game a lot more fun. Dig into even more of the lore and history behind the
World of Warcraft in WoW Insider's Guide to Warcraft Lore