Last week we talked about the Old Gods, both ones we know as of right now and ones we can speculate upon come the Cataclysm. This week, we turn an unblinking gaze upon the master of unblinking gazes, the Old God that has arguably the most direct impact upon all of Azeroth. Not only did it indirectly create the nerubians and directly altered the qiraji into their modern form, not only did it battle a Titan to a standstill, but its connection to the Twilight's Hammer and their demented leader Cho'gall means that even during the upcoming Cataclysm, the consequences of its actions are unfolding.
Most interestingly, this Old God did not even have a name until its own creations gave it one.
The history of C'Thun on Azeroth dates back to before it had a name or an army of arthropod followers. One of several of its kind to either discover or create Azeroth (sources argue, although it's telling that most sources that claim the creation of Azeroth for the Old Gods tend to be, well, insane cultists for the Old Gods), it existed for countless millennia before the war with the titans, bending Azeroth's elementals to its will alongside its fellows and waging ceasless chaotic elemental war between proxy elemental lords for its own amusement.
It's difficult to tell how long this state of affairs continued or if it started before or after the titans' first efforts to shape Azeroth. Since the ancient troll empires had records of the titans, it is entirely possible that the titans came and left many times, perhaps in response to the Old Gods' machinations, as implied in the Curse of Flesh dialog.
What is known is that the titans and Old Gods eventually went to war over Azeroth and that the Old Gods lost. They had managed to infiltrate the world so thoroughly that it would have destroyed Azeroth to destroy them. While not entirely unwilling to unmake their creation (as the Algalon protocol would show), they were loath to do so unless it was a complete last resort. So instead, they imprisoned their enemies in the core of the very world they'd sought to dominate, fashioning prisons like Ulduar to hold them forever.
Well, all but one.
Alone among its fellows, one Old God did battle against a titan and brought that titan down, although whether it died or not is unknown. (Recent speculation about the Titanic Watcher known as Tyr makes it plausible that C'thun cost that loyal minion of the titans his hand as well, as the description of the entity that maimed Tyr and of the entity who would be named C'thun are very similar.) This not-yet-C'thun entity was imprisoned beneath the surface of the world, as were the others (perhaps under the complex that would become known as Ahn'Qiraj when his qiraji slaves managed to seize control of it) -- but unlike them, it had displayed the strength to defeat a titan and was not so easily bound.
Over vast stretches of time, it worked its malevolent slumbering will, not sleeping, not dead, eternally seeking to subvert and corrupt the creations of its enemies. The very Well of Eternity gave it the proto-silithid, who would become the aqir, which would lead to the nerubians and qiraji. The qiraji would come to C'thun and conquer for it the titan complex that lies today in the sands of Silithus, the fortress temple of Ahn'Qiraj. And in its corrupted titanic halls, the great dark god would dream of conquest over the world entire.
Over the thousands of years that passed, through the Sundering that shattered Kalimdor, past the final destruction of the ancient Troll empires at the hands of the Tidehunter and his minions, the Old God that had become C'Thun waited, until at last its forces had grown strong enough to contest the hated kaldorei for dominion over Kalimdor itself. Thus began the War of the Shifting Sands, which would see corrupted titan creations like the tol'vir battle side by side with silithid hordes and qiraji leaders to push the night elves out of Kalimdor.
C'Thun's plan nearly succeeded. At first, the night elves held fast and defeated the qiraji in several battles, thanks to the brilliant leadership of an archdruid. C'Thun was not so easily balked. His followers managed to discover the one weak spot of the formidable Fandral Staghelm, the druid leading the night elf resistance against the qiraji: his deep and abiding love for his son. Exploiting the elder Staghelm's pride in and love for his boy, the qiraji General Rajaxx managed to destroy the night elf commander's resolve in one battle.
Following Valstann's death, the kaldorei were driven out of Silithus by the qiraji, and victory for C'Thun seemed nigh. Perhaps if they'd stopped at the border to Silithus and entrenched themselves, we would now be living in a world dominated by the servants of the Old God. But in pursuing the night elves, the qiraji crossed the "god lands," the titan nature preserve of Un'Goro. In so doing, they exposed themselves to the devices created by the titans to preserve it. Furthermore, while Fandral Staghelm was not persuasive enough to commit the Bronze Dragonflight to his cause, an attack by the qiraji themselves (possibly out of desperation due to their discomfort with Un'Goro) stirred the servants of Nozdormu and eventually of the red, green and blue dragons as well.
Together, these forces drove the frenzied qiraji back. Despite the power of creations such as Ossirian the Unscarred, the twin emperors of the qiraji could not prevail against the night elf druids and sentinels with the aid of four dragonflights at their backs, but neither could those forces hope to win out against the Old God itself in its den. Rather than risk so apocalyptic a conflict, a solution was enacted that sealed the qiraji and C'Thun up insider their very fortress, the city complex of Ahn'Qiraj itself. Fandral Staghelm, entrusted with the Sceptre used to seal Ahn'Qiraj, shattered it out of bitterness over the death of his son.
For a thousand years, C'Thun and his servitors lay confined within their citadel prison. Eventually, the silithid began to find ways to tunnel through the earth and indirectly menace Kalimdor once again. This led to what would turn out to be the last successful joint operation of the Horde and Alliance, the Might of Kalimdor led by Varok Saurfang. While the Might led the armed forces of both factions into battle, the Cenarion Circle enlisted mighty heroes to recombine the shattered Scepter of the Shifting Sands and breach the very walls of Ahn'Qiraj. These heroes would seemingly do what even the titans could not and kill the Old God in his lair.
However, when one refers to the Old Gods one speaks of beings that may not be able to die, as such. Although supposedly "dead" and its qiraji followers dispersed, C'Thun still managed to draw Cho'gall to the ruins of AQ, still managed to twist and deform the ogre mage beyond all recognition, and still managed to send him and his Twilight's Hammer cultists off to bedevil a group of mortal heroes in an attempt to kidnap the son of Medivh. And although those forces were supposedly defeated as well, it's telling that the Twilight's Hammer has only grown in strength and can be seen hard at work come the Cataclysm. C'Thun's best trick may well be convincing this host of enemies that it is dead.
Next week, Yogg-Saron rises.