Dark Exile

"It was a shining - but brief - moment for the Mage Clans when they set aside their differences and worked together against the common enemy. The Horadrim relentlessly pursued the Three across the desolate Empires of the East, and even into the uncharted lands of the West, leaving the Archangel Tyrael's hands unblemished."

- Horazon

The Dark Exile refers to the banishment of the Prime Evils to Sanctuary by the Lesser Evils. This article also covers the Hunt for the Three Prime Evils on Sanctuary, though most sources treat this as a separate event.

Background
"How dare you question! How dare you deny yourselves victory! Long have the Primes lorded over us. Long have they thought themselves our betters. Diablo...Diablo will fall, as will the rest. Do not be swayed or led to fear by him. Do not, for each of you will reign. Each of you will share the power we will earn."

- Belial addressing Duriel and Andariel

The Dark Exile had its origins in the aftermath of the Sin War, and consequent cessation of the Eternal Conflict, as per the pact made between Mephisto and the Angiris Council. The Prime Evils nonetheless turned their attention to the perversion of human souls, for they realized that mankind was key to their eventual victory over Heaven. This deviation from the norm caused many of the Lesser Evils to question the authority of the Three, and so brought about a great rift between the Prime Evils and their servitors. That the Primes had not revealed the existence of Sanctuary to the Lesser Evils when they first discovered it prior to the Sin War had already soured relations between them and their lesser brothers, and Deckard Cain would speculate hundreds of years later that this deception added to the Lessers' decision to rebel.

In their ignorance, the Lesser Evils began to believe that the Three were afraid to continue the war with Heaven. They considered themselves innately superior to humankind, and that the Eternal Conflict was theirs alone to fight. Frustrated by the cessation of the war, Azmodan and Belial saw the situation as their chance to overthrow the Prime Evils and take control of Hell for themselves. Belial manipulated Azmodan into revolt and the demon lords made pacts with their brethren, assuring them that humanity would not deter them from seizing victory in the Eternal Conflict. Andariel and Duriel had their doubts at first, afraid that they would fall in the coming conflict. Belial however, kept them in the fold. Azmodan and Belial devised a plan to end the stalemate, achieve victory in the Sin War and ultimately ride the bloody crest of the Great Conflict straight into the very arms of Armageddon. Thus, a great revolution was set into motion as all of Hell went to war against the Three Brothers.

The Uprising and Aftermath
"So it came to be that there was a great revolution within the Burning Hells known as the Dark Exile. The Lesser Evils overthrew the three Prime Evils and banished their spirit forms to the mortal realm. The Demons Belial (the Lord of Lies) and Azmodan (the Lord of Sin) fought to claim rulership of Hell during the abscence of the Three Brothers. All of Hell polarized between the factions of Belial and Azmodan while the forces of the High Heavens continually battered upon the very gates of Hell."

- Dark Exile (excerpt)

Hell became embroiled in civil war as the Prime Evils were turned upon. To their credit, the Prime Evils fought with devastating power, annihilating a third of Hell's treacherous legions. In the end, however, they were overcome by the Horned Death led by the traitors Azmodan and Belial. The Prime Evils, weakened and bodiless, were banished to the mortal realm where Azmodan hoped that they would remain trapped forever. Azmodan believed that with the Three set loose upon humanity, Heaven would be forced to turn their focus upon the mortal plane, thus leaving the Gates of Heaven abandoned and defenseless. According to folklore, a single demon devastated half of Hell in anger after the Prime Evils' defeat. Those few demons who still pledged allegiance to the Three Brothers fled the wrath of Azmodan and Belial, escaping to Sanctuary to seek out their lost masters.

As the fires of war died down, Azmodan and Belial began to argue over which of them held the higher authority. The pact that they had made quickly fell to ashes as the two demon lords took up arms against each other. The legions of Hell that remained were polarized behind either warlord, launching themselves into a second civil war. One account states that there was no falling out however, and that the two Lesser Evils began a scheme to subjugate all life to their will. In truth however, the two lords did indeed do battle, and both claimed massive realms as their own. By the Darkening of Tristram, Azmodan had held the upper hand for quite some time. Of note, Skarn was also able to claim swathes of Hell as his own. Eventually, both Lesser Evils would turn their attention to Sanctuary.

In truth, the Primes' banishment to the mortal realm had been masterminded by the Primes' themselves. Izual had told them of the soulstones, and helped them devise the scheme. It was intended that through the use of the soulstones, they would corrupt the Worldstone, and through it, humanity, and its nephalem potential.

The Hunt for the Three
"Nearly three hundred years ago, it came to be known that the three Prime Evils of the Burning Hells had mysteriously come to our world. The Three Brothers ravaged the lands of the East for decades, while humanity was left trembling in their wake. Our order - the Horadrim - was founded by a group of secretive Magi to hunt down and capture the three Evils once and for all."

- Tale of the Horadrim (excerpt)

The coming of the Three marked a time of evil in the history of Sanctuary unlike any other. The cataclysm that followed their arrival brought immense change to the world when the Three unleashed their hellish followers upon the world. These followers wrought great destruction upon the lands of Sanctuary. That which was not consumed by the arrival of this malevolence was often twisted and altered by the effects of the resulting chaotic forces. Many of the native creatures inhabiting the world became vile and depraved shadows of their natural forms. A world that once allowed the unfettered development and expansion of mankind became a place where only the strongest could survive.

The Prime Evils roamed the east of Sanctuary, feeding upon the lusts of men, leaving chaos in their wake. Entire nations were led into brutal and petty wars. Their exile from Hell had left the Three with an insatiable hunger to bring suffering and pain to all who would not kneel before them, and so the Three Brothers ravaged the lands of the Far East. The Three could inhabit the bodies of humans, and used this ability to control political and religious figures, allowing them to deceive the people of Kehjistan.

Eventually the presence of the Primes was discovered by Tyrael, Archangel of Justice. Knowing that the Angiris Council had spared mankind by a single vote at the end of the Sin War, the angel dared not inform his brethren that Hell threatened to corrupt humanity once again. Somehow, he had to intervene without alerting Heaven to the situation. To this end, he gathered various individuals from various Mage Clans. They were all strangers to one another, but were selected because these men were the most likely to succeed in Tyrael's mind. Naming this group the Horadrim, Tyrael gave them three soulstones, each a shard of the Worldstone. Each of these soulstones would be used to contain the essence of a single Prime Evil. The soulstones allowed the Horadrim to track the Primes, even when their true forms were hidden within mortal shells.

The Cube
A device simply called "the Cube" was designed by Zoltun Kulle; one of the mages Tyrael had chosen. The Horadrim agreed that it would be a necessary device if their hunt was to succeed. However, its creation was marred by dark methods and disastrous results, resulting in the order quickly determining that it was too dangerous for anyone to continue using. Creating the weaker Horadric Cube in its stead, they entrusted the first Cube to a secret organization of s on Mount Arreat, who kept it safe from everyone, including the rest of their tribe.

The Binding of Hatred
The power of the soulstones proved to be much more difficult to employ when used against the great Prime Evils. Voraciously disposed to possessing hapless mortals, the Three Brothers found that they were immune to the effects of the stones while occupying human souls. Thus, the Horadrim were forced to kill the innocent victims of the Three so that their demonic essences could be subjected to the soulstones.

During the hunt for Mephisto, the Lord of Hatred frequently made use of undead minions, and common soldiers were hard pressed to combat the seemlessly endless tides of undead that he summoned. During the assault on the demon's Fortress of Bone, the army the Horadrim led was nearly overwhelmed by these beings, but were able to nullify the demon's ability to resurrect soldiers through a type of magic and won the day. After five years, the Horadrim located Mephisto in or around one of the urban centers of Kehjistan. They succeeded in capturing and imprisoning the demon, but the fight cost many innocent lives. The Horadrim thus vowed to avoid confronting another Prime Evil in a populated area.

The Horadrim also had to decide what to do with Mephisto's soulstone. Tal Rasha decided to entrust it to the monks of Zakarum, whom he had an affinity for, and believed could be trusted to guard it. As the Horadrim continued their hunt for the remaining Primes, the Zakarum began building the temple city of Travincal, under which Mephisto's soulstone would be guarded. While the act of construction drew many followers to Zakarum, Mephisto's presence would have disastrous consequences for the religion in later centuries.

The Binding of Destruction
"What is the strength of man against Hell itself?"

- Baal to the Horadrim

In time, Diablo and Baal journeyed across the Twin Seas to the deserts of Aranoch, the Horadrim in close pursuit. 58 days after the hunt had begun, Baal took refuge in the city of Lut Gholein. Tal Rasha had believed that Baal had been headed north for Scosglen, but regardless, for three days, the Horadrim waited patiently. The demon then fled into the scorched wasteland, but the harsh desert offered no solace from his persuers. Turning to fight, Baal unleashed his powers against the Horadrim. Reportedly, as very ground itself gave way, and the combatants fell into a network of subterranean caverns. In truth, however, the battle took place on the surface, as the Horadrim fought against Baal's demons. Tal Rasha engaged Baal in single combat, until Kulle, leading the rest of the Horadrim, arrived to join the fray.

It is here, that accounts vary. One states that in a desperate attempt to survive, Baal hurled a devastating spell against Tal Rasha, shattering the Amber Soulstone. However, it was not enough, and the raging demon lord was subdued. Tal Rasha, gathering the largest of the stone's shards, trapped Baal's destructive essence within it. A different account from Nor Tiraj however, states that it was Kulle's inability to properly handle the stone in battle that led to its destruction. In truth, the former account holds more weight. Whatever the truth, the outcome was the same&mdash;Baal was contained in the shard, but it would not hold him indefinitely.

Once again, accounts differ, as to whether it was the suggestion of Kulle or Tal Rasha that a human act as a surrogate soulstone, using the shard as a conduit to their body. Deckard Cain would theorize centuries later that Kulle's role was downplayed in writings due to the falling out he had with the Horadrim. But again, whatever the truth of the matter, Tal Rasha volunteered for the role, fated to wrestle with the demon for eternity. It was here that Tyrael appeared once more, telling Tal Rasha that his sacrifice would be remembered. He then led the men through the tunnels into the burial chambers of long-dead kings. In one of the largest tombs, the Horadrim built a binding stone, etched with runes of containment, held fast to the chamber's walls by unbreakable chains. Tal Rasha ordered his brethren chain him to the stone, after which Tyrael jammed the soulstone into his chest, leaving him to wrestle with Baal's spirit for eternity. Sorrowfully, the Horadrim sealed the chamber and departed.

The Binding of Terror
In the wake of Tal Rasha's sacrifice, Jered Cain became the leader of the Horadrim. They began searching for Diablo, in a hunt that would take them the better part of a decade. Finally, in the year 1019, fifteen years after their quest had begun, they found the Lord of Terror in the lands of Khanduras. In a battle that nearly cost the Horadrim their lives, Diablo was defeated, and his spirit imprisoned. The soulstone was hidden in a labyrinthine cave system near the River Talsande. Tyrael then appeared before the Horadrim a final time, commending them for their victory. He ordered that the site must be guarded for all time, lest the Lord of Terror someday walk among mankind once more. The Horadrim thus built a small monastery and a system of catacombs within the caves.

The hunt was over.

Legacy
"Presuming the Three to be vanquished, the Horadrim's unstable fellowship began to dissipate. Abandoning their sacred charge to safeguard the three Soulstones, the disparate Mage Clans began to squabble amongst each other over petty differences. Their conflicts not only dissolved their brotherhood, but strengthened the Evils which they had buried beneath the cold earth."

- Horazon

As the generations passed in Khanduras, the Horadrim diminished in number. With no quests to undertake, and too few sons to replenish their number, the Horadric order faded into obscurity, Their greatest fear was that the three Prime Evils would one day reunite. However, they took squabbling among themselves over petty differences, leading to the dissolution of their brotherhood.

The Horadrim's fear was well founded, as each of the Primes returned to wreak havoc on the mortal world. Mephisto was able to corrupt the Zakarum faith from within, subverting their guardianship over his soulstone. In the Darkening of Tristram, Diablo returned to the world of Men, eventually taking Aidan as his host and departing east to reunite with his brothers. This included Baal, still wearing the guise of Tal Rasha his powers increased thanks to his host. It was only thanks to a group of heroes that their plans to corrupt the Worldstone and retake their place in Hell were thwarted, though not without cost, as the Worldstone itself was destroyed.

Even now, the legacy of the Dark Exile endures. Today, the areas most tainted by the Prime Evils' arrival in the mortal realm are the Western Kingdoms, the desert regions of Aranoch, and the jungles of Kehjistan. Unnatural and evil forces influence most, if not all, of Sanctuary's native creatures to at least some degree. Lairs of demonic nobility remain in the land, and the sight of these creatures assisting Hell's minions grows more common as one nears these lairs.

The events of the Dark Exile have been written on extensively, including works such as the Dark Exile Scrolls, Librarius Ex Horadrim, and the Book of Cain.

Trivia

 * In the Diablo manual, it is stated that the Prime Evils spent "countless centuries" on Sanctuary before being captured. This was rendered null by Book of Tyrael, in which the timeline provided established that the Prime Evils were only active for decades before all being imprisoned.


 * In the same manual, it was stated that both Mephisto and Baal were buried under the "desolate eastern sands." While this remains true for Baal, this was made null for Mephisto as early as Diablo II, where it was established that he was imprisoned in Travincal (a jungle area).