War against the Elder One

The war against the Elder One was a war between the reestablished Inquisition and the Elder One, a powerful magic-using being. It coalesced in 9:41 Dragon amidst the chaos of the Mage-Templar War and the War of the Lions as the Elder One manipulated the Mage Rebellion, the Templar Order, the Grey Wardens of Orlais and several senior members of the Orlesian nobility to serve his purposes, threatening the whole of Thedas.

Background
At some point between 9:31 and 9:37 Dragon, the darkspawn and former magister Corypheus awoke in a Grey Warden prison in the Vimmark Mountains that had held him for centuries. Unable to escape the prison due to blood magic seals forged by Malcolm Hawke, Corypheus resorted to using his powers to influence his Grey Warden jailers as well as a group of Carta dwarves. When Hawke, a child of Malcolm, arrived in nearby Kirkwall, Corypheus used the Carta to lure Hawke to the prison in order to break the seals. Corypheus was freed and promptly killed by Hawke, but the magister had the regenerative capabilities of an Archdemon and was able to escape by possessing the Grey Warden Larius or Janeka.

Corypheus spent the subsequent years preparing a plan to both restore the Tevinter Imperium to its ancient glory and return to the Black City so that he could claim the Maker's throne and become the new god of the world. Fortuitously, Corypheus acquired the Orb of Destruction, a powerful magical artifact, from the elf Solas, giving him the power necessary to bring his plan to fruition.

As the Mage-Templar War and later the Orlesian Civil War raged in the background, Corypheus began to assemble an army with the intention of conquering southern Thedas. Allying with the Tevinter-supremacist Venatori, the magister used his powers to deceive the Grey Wardens of Orlais into believing they were experiencing the Calling and were about to die. Desperate to find a way to kill the remaining two Old Gods before a new Blight could erupt, Warden-Commander Clarel de Chanson accepted the offer of Livius Erimond, a Venatori magister, to use a blood magic ritual that would create a demon army, thus bringing the Grey Wardens under Corypheus's control.

The Breach
Hostilities effectively began in 9:41 Dragon during Divine Justinia V's conclave at the Temple of Sacred Ashes, a Chantry-led attempt to negotiate an end to the Mage-Templar War. Corypheus and a number of Grey Wardens interrupted the proceedings. Justinia V was sacrificed to unlock the Orb of Destruction's power, and in that moment the Breach was created, rending the Veil between Thedas and the Fade. An unwitting witness to the sacrifice came into contact with the Orb and was branded with a magical mark called the Anchor, which could open and close the Breach and the numerous smaller Rifts scattered across the land. This would prove to be a major setback to Corypheus's plans, as he had intended to gain the Anchor for himself to physically enter the Fade.

The lone survivor of the Breach was the individual who had been given the Anchor. Suffering from memory-loss and the Anchor's own debilitating effects, the survivor was recovered from the ruins of the Temple of Sacred Ashes and brought to the nearby village of Haven to recuperate for questioning by Seeker Cassandra Pentaghast and Leliana, the Right and Left Hands of the late Divine. Upon waking, the survivor was led to the Breach in the hope that they could use the Anchor to seal it; while the survivor lacked the power to seal it completely, they managed to calm it and stop it from spreading. Afterwards, the survivor was hailed as the "Herald of Andraste" and became one of the founding members of the new Inquisition, which Cassandra proclaimed in accordance with a writ issued by Justinia V before the conclave.

The events surrounding the Breach had far-reaching implications. The Divine and most of the Chantry's leadership were dead, leaving the Chantry leaderless and floundering. The leaders of the Mage Rebellion and Templar Order had also perished, reigniting the Mage-Templar War. Countless demons began emerging through the Rifts, terrorizing civilians throughout the land. Lastly, the Inquisition had been reformed with the goal of sealing the Breach and bringing whoever had caused it to justice.

Redcliffe and Therinfal
Despite losing the Anchor, Corypheus continued building up his army and planted the seeds of corruption within the Mage Rebellion and Templar Order. The surviving mages who attended the conclave retreated to the village of Redcliffe with the permission of Ferelden's monarch. The Venatori magister Gereon Alexius was dispatched to bring the mages into the fold; using time-altering magic, Alexius ostensibly rescued the mages just before they were attacked by a group of Templars and offered an alliance. Desperate, Grand Enchanter Fiona accepted, indenturing herself and her fellow mages to the Venatori.

Meanwhile, Lord Seeker Lucius Corin, leader of the surviving Templars, was replaced with an Envy demon loyal to Corypheus. As Corin, the demon widened the split between the Order and the Chantry by openly spurning Revered Mother Hevara at Val Royeaux, then regrouped the Templars at Therinfal Redoubt. There, the Templar officers were introduced to red lyrium and twisted to serve Corypheus as the Red Templars.

At Haven, the Herald of Andraste and their advisors Cullen, Leliana, and Josephine Montilyet began to flex the muscles of the fledgling Inquisition by gathering allies and working to restore order. The Breach yet loomed in the sky, however, and it soon became evident that the assistance of the mages and Templars would be necessary to fully seal it. The Herald was presented with a choice: negotiate first with Magister Alexius at Redcliffe to gain an alliance with the mages, or approach Lord Seeker Lucius and the Templars at Therinfal. Both options held risks, as Alexius's requested audience with the Herald was obviously a trap, and Lucius's recent behavior and self-imposed isolation made him unpredictable.

Depending on whom the Herald decided to pursue first, the Inquisition conscripted or allied with the mages or Templars, depriving Corypheus of some of his forces. Contact with the other faction was lost; the mages at Redcliffe vanished with the Venatori, or the Templars at Therinfal became the Red Templars. The Inquisition learned of Corypheus's involvement, though knew the magister only as a mysterious individual called "the Elder One".

Battle of Haven
Returning to the Temple of Sacred Ashes, the Herald finally sealed the Breach with the aid of the mages or Templars. Although many Rifts remained and the Elder One was at large, the Inquisition believed the main threat was over. Together with the winding down of the Mage-Templar War, the Inquisition celebrated the end of weeks of strife and uncertainty.

That night, Corypheus led the bulk of his army, either the Venatori under Calpernia or the Red Templars under General Samson, in a surprise assault on Haven and the Inquisition to take back the Anchor from the Herald. The Herald rallied their forces and fought off the initial wave before using a trebuchet to trigger an avalanche that wiped out the bulk of the enemy host. Corypheus countered by unleashing his high dragon, which effortlessly broke and scattered the Inquisition defenses. The Inquisition and people of Haven fled to Haven's Chantry for shelter, but with what appeared to be an Archdemon on his side, Corypheus's victory was all but certain. Hope was restored by Grand Chancellor Roderick, who divulged the existence of a hidden trail from Haven that could be used as an escape route. Upon learning that Corypheus sought the Herald personally, the Herald decided to try and distract the magister long enough for everyone else to flee safety.

As the Herald fought another wave of enemies and redirected a trebuchet, the dragon attacked once more. Corypheus, revealing himself as the Elder One, arrived and attempted to remove the Anchor using the Orb of Destruction, but to no avail; the Anchor was permanently bound to the Herald. Frustrated, Corypheus decided to kill the Herald and start over, but the Herald triggered the trebuchet and started another avalanche, this one directed at Haven. Corypheus escaped with his dragon, while the Herald managed to reach the old tunnels beneath Haven before the avalanche hit. Making their way through the tunnels, the Herald eventually caught up with the surviving Inquisition forces in the Frostback Mountains.

The Inquisition had been dealt a serious blow and was in disarray. They were demoralized, had lost their base of operations, and feared the outbreak of new Blight, a danger implied by Corypheus's Archdemon-like dragon. Encouraged to take the lead by Revered Mother Giselle and the apostate elf Solas, the Herald guided the Inquisition through the mountains to the abandoned fortress of Skyhold, which became the organization's new headquarters. For their contributions, the Herald was formally honored with the title of Inquisitor, the leader of the Inquisition.

Investigating the Grey Wardens
As the Inquisition recovered, the Inquisitor's attention turned to the recent disappearance of the Grey Wardens of Orlais. Brought into contact with the Champion of Kirkwall, Hawke, the Inquisitor was informed that Corypheus had the power to manipulate Grey Wardens and imitate the Calling. Fearing that Corypheus had already done so, the Inquisitor followed the Champion to meet a Grey Warden in Crestwood (either Stroud, Alistair, or Loghain Mac Tir ) who explained his fellow Wardens were indeed hearing the Calling and had committed to a blood magic ritual designed to prevent future Blights.

The Inquisitor, Hawke, and Hawke's Warden friend traveled to the Western Approach, where the other Wardens were carrying out their ritual under the direction of Magister Livius Erimond. Unbeknownst to the Wardens, the ritual bound the demons created by the Wardens' sacrifices to Corypheus, not themselves; Erimond had deceived them as part of his master's plan. Erimond then attempted to control the Inquisitor through magical manipulation of the Anchor, only for his foe to counter and sent him fleeing for Adamant Fortress.

Siege of Adamant Fortress
The Inquisition later plotted a siege of Adamant. Due to the fortress' age, it would not withstand modern siege equipment, which was provided to the Inquisition by Lady Seryl of Jader, and Leliana provided tactical information to limit the field of battle. The Inquisition then laid siege to the fortress, only to preoccupy the Wardens while the Inquisitor finds Erimond.

Arriving as the Wardens were in the midst of summoning a Nightmare demon, the Inquisitor exposed Erimond, bringing Warden-Commander Clarel de Chanson and others to their senses and they turned against the Venatori. Erimond then summoned Corypheus' archdemon to attack. In the middle of the battle, a dying Clarel struck the archdemon's underbelly, accidentally destroying a portion of the fortress, causing the Inquisitor, Hawke and their Warden ally to fall as the Anchor accidentally opens a rift, sending them into the Fade. They managed to return to the physical world through the rift at Adamant, though either Hawke or the Warden ally were left behind to fend off the Nightmare. The Inquisitor then sealed the rift, banishing all the demons. With the battle over, the Inquisitor had to choose between allying with the remaining Grey Wardens or exiling them from Orlais for their actions.

The battle also hardened the Inquisition's soldiers, making them battle-ready veterans. Meanwhile, Corypheus had lost his demon army and had only a few dozen enthralled Wardens under his control.

Intrigue at Halamshiral
With another of Corypheus's plans foiled, the Inquisitor next had to deal with an assassination plot against Empress Celene Valmont I of Orlais, a plot uncovered during the events of Redcliffe or Therinfal; if Celene is killed, it would throw Orlais into chaos. The Inquisition attempted to send a warning to the Empress about the danger to her but the messages were intercepted. However, as Celene was hosting peace talks in the form of a grand ball at the Winter Palace at Halamshiral, the Inquisitor attends the ball as a guest of Grand Duke Gaspard de Chalons, who was contending with Celene over the throne, to unmask the assassin. Ambassador Briala, leader of Orlais' rebel elves, was also invited in a bid for Celene to gain an alliance with the rebels. All three parties began currying for the Inquisition's support.

During the ball, the Inquisitor investigated strange goings-on at the Winter Palace, from the murder of Briala's agents to the body of a Council of Heralds emissary with a Chalons crest on the murder knife. Eventually, the Inquisitor discovers that the assassin is Grand Duchess Florianne, Gaspard's sister, who was allied with Corypheus, having been promised all of Thedas to rule once she assassinated Celene. Having successfully lured the Inquisitor away from Celene, Florianne leaves her company of Venatori and demons pouring out of a Fade rift to deal with the Inquisitor while she returned to the ballroom to make her move. However, the Inquisitor managed to survive the ambush and returned to the ballroom before Florianne could make her move. The Inquisitor can then either allow Florianne to kill Celene or thwart her. Afterwards, the Inquisitor has a say in who rules Orlais.

Either way, the Orlesian Civil War had been brought to an end and Orlais allies with the Inquisition.

March on the Arbor Wilds
With his plans foiled, Corypheus uprooted his strongholds and concentrated his remaining forces on scouring the Arbor Wilds for elven artifacts. Morrigan, Celene's arcane advisor and newly appointed liaison to the Inquisition, suspected that Corypheus was seeking an eluvian, a magically elven mirror that could allow him to enter the Fade without need of the Anchor.

With the support of the Orlesian armies, the Inquisition marched on the Arbor Wilds and engaged Corypheus' forces. However, the invasion had awoken ancient elven sentinels, who were protectors of the Temple of Mythal, who engaged both sides. The Inquisitor, along with Morrigan and a few companions, fought through the blockades, managing to catch up with Corypheus as the darkspawn was in the midst of confronting a group of sentinels. Corypheus was then seemingly destroyed by a magical barrier, only to be reborn in the body of a nearby Warden. The Inquisitor's party quickly took refuge inside the temple as Corypheus summoned his dragon to attack.

The Inquisitor's party then navigated the temple, either fighting through the sentinels or allying with them, before confronting and besting Corypheus' general, Samson/Calpernia. Afterwards, the Inquisitor or Morrigan drank from the Well of Sorrows, which was the key to the resident eluvian, to render it useless. At the same time, Corypheus managed to storm his way into the temple. The Inquisitor's party used the eluvian to return to Skyhold as a mysterious feminine entity arose from the Well, which blocked Corypheus and smashed into the eluvian, destroying it.

As Corypheus and his archdemon fled the field, the Inquisition was able to rout the darkspawn's army.

Final confrontation
In a last desperate attempt to enter the Fade, Corypheus returned to the Temple of Sacred Ashes to reopen the Breach with the Orb of Destruction. With a small group of Inquisition as his audience, he proclaimed that the Maker was false and he would be the new god and demanded their fealty. When the soldiers defiantly refused, Corypheus responded with a blast of energy before unleashing a pair of terror demons against them.

The Inquisitor quickly responded and arrived on the scene. Corypheus then suddenly levitated the temple into the sky to ensure that his nemesis couldn't escape. His archdemon then attempted to attack, only to be tackled out of the way by another dragon (either the Guardian of Mythal, if the Inquisitor drank from the Well, or a transformed Morrigan, if she drank). Eventually, the archdemon was able to down its opponent, only to be killed by the Inquisitor soon after, causing Corypheus' ability to leap into other tainted bodies to be disrupted, rendering him vulnerable. With his defeat certain, Corypheus futilely called out to his Old Gods for aid, only for the Inquisitor to rip the Orb from his hand with the Anchor and used it to seal the Breach. The Inquisitor then used the Anchor to open a rift, vaporizing Corypheus.