Battle of Elturel

The Battle of Elturel was the final engagement of the Damnation of Elturel, fought in Tarsakh of 1498. The battle was a tripartite engagement, which saw the Blood Legions of the Nine Hells attempting to defend the city Elturel from the demons of Yeenoghu, who wished to slaughter the city's denizens before they could be bathed in the River Styx, losing their souls to join the ranks of Hell. Meanwhile, the mortals of Elturel fought to defend their home while buying time for the Lost Star Detectives to return enough energy to the Companion to return their city to the Material Plane.
The Battle of Elturel is also best remembered for the redemption of the Archduke of Avernus, Zariel, who partway through the fighting changed sides from the force of Hell to defending the city. 
Though the engagement was no more than a few hours for its participants, the shifting correlation of the passage of time between Avernus and the Material Plane meant that the battle was fought over the course of the entire month of Tarsakh.

The Conflict

Prelude

On the 2nd of Eleasis, 1497, the city of Elturel and all within were teleported to Avernus in the Nine Hells by the city's second artifical sun the Companion , fulfilling the terms of a pact signed fifty years previous. Elturel's civilian and military leadership had long been infiltrated by the cult of Zariel, and upon their arrival into Hell most of the heads of government and the commanding officers of the Hellriders and the Order of the Companion transformed into devils, escalating the chaos.
The transformed Hell Knights began prowling the streets alongside regular cultists of Zariel, hunting down the remaining Hellriders, members of the Order of the Compannion, and their family members to turn them into devils as well by the hidden terms of the Creed Resolute, while other citizens were left alone. However, demons had also arrived in the city to kill any that they could. Elturel was chained over the River Styx, kept aloft by the purity of souls within, and the forces of Hell attempted to make infernal pacts with the residents to corrupt them and thereby lower the city further until it was completely submerged in the river, drowning every Elturian and rebirthing them as devils for the Blood Legions. The forces of the Abyss were dispatched to kill as many Elturians as possible to prevent their resurrection as their hated infernal enemies.
As the situation in Elturel devolved, a few safe havens were established. In Shiarra's Market, the vampire and former High Rider of Elturel Klav Ikaia revealed himself to be alive after the 1447 Reign of Vampires. He and a small force of dhampirs he had been training in the city's Maze took control of the market and turned it into a refuge. In High Hall, Grand Duke Ulder Ravengard of Baldur's Gate established a sanctuary with his Flaming Fist guards and a few Hellriders, though its weakened defenses were constantly assaulted by the city's devils. Finally, Helm's Shieldhall contained the bulk of the surviving Hellriders, but it too was under siege by devils who sought to kill the Hellriders within.
The arrival of the Lost Star Detectives on the 20th of Eleasis marked a turning point for the situation in Elturel. The Detectives first secured most of the Dock District, though they left a growing stronghold of demons on the docks themselves alone, before securing High Hall and ending the Siege of Helm's Shieldhall. The destruction of most of the Hell Knights' forces during the siege greatly improved the safety of moving around Elturel, albeit in large patrol groups, and the Shieldhall, High Hall, and Shiarra's Market continued to grow and become much needed strongholds against the devils and demons that remained in the city. The death of the devils holding the bridges connecting the Dock District with the two western districts also allowed for collaboration between the undead forces in the market and the Elturians in High Hall and the shieldhall, though the groups didn't trust one another.
As the situation continued and stablized, the descent of Elturel into the Styx also slowed down, as the Detective Alesine Zadava warned all she could find about the danger of signing devil contracts. Because of this, the city's descent into the Styx relied just as much on the chains binding it as it did corrupting the souls of those within. Seeing no more they could do in Elturel, the Detectives then departed for the plane of Avernus itself, seeking a way to free the city and return it to the Material Plane
Another boon to the city came with the arrival of the kirin Enki, who was freed by the Lost Star Detectives during their exploration of Hell. Enki, alongside his Elturian companion Thei Linden, settled at Maiden's Leap, and Enki's celestial nature purified the water of Bellandi fountain, allowing for fresh and healing water to be available to those that needed it. As the sick and injured gathered near the fountain, a detachment of Hellriders and members of the newly formed anti-vampire Order of the Sun stationed themselves at Maiden's Leap, creating a fourth safe haven. 
When the Lost Star Detectives returned to Elturel, they had with them the tools and knowledge needed to free the city. The chains that bound the city were set to automatically release upon the destruction or nullification of the pact keeping it in Avernus and they possessed keys that would allow them to open up the Companion, allowing them to reverse its energy to teleport the city back to the Material Plane. However, they were missing a critical component: the half of the pact binding the city that was in Archduke of Avernus Zariel's possession. The Detectives planned to confront Zariel by luring her to the city, but doing so would no doubt launch the final attempt by the forces of Hell to sink the city. In addition, a massive demonic army had gathered outside of Elturel during the Detectives' absence, summoned by the demon lord Yeenoghu, and when the demons saw the city about to be sunk, they would launch their attack to try and slaughter all within before that could happen. Seeing no other option but to fight to give the Detectives enough time to save them, the various factions of the city began final preparations, gathering all the survivors they could in one of the city's four strongholds.

Deployment

The forces defending Elturel were stationed in one of four locations. High Hall, the seat of Elturel's government on the Material Plane, had been turned into a safe haven for refugees that were sheltered in the catacombs beneath the temple of Torm. Above ground, the defenders built a series of barricades surrounding the temple and throughout the courtyard, leading to the blocked entrance to the compound. Breaches in the walls from earlier fighting and the city's violent teleportation were patched as best as the defenders could, and Hellriders and other trained fighters were stationed on the walls. The defenses and organization before the battle were led by Grand Duke Ulder Ravengard, whose decades of command experience proved invaluable during the pre-battle preparations.
At Maiden's Leap, where the sick and injured gatehred around the purified water of Bellandi Fountain, Hellriders and members of the Order of the Sun stood ready. Oil was used to slicken the wall at the back of Maiden's Leap, while trees were cleared from the Gardens to give a field of fire and to build barricades. Nearby buildings were also torn down for that purpose. However, the area was poorly defended from the air due to its location, and aerial protection was left in the hands of the ki-rin Enki and the Elturian Thei Linden, who was to ride on Enki's back and shield the civilians from above.
At Helm's Shieldhall, the holes in the defenses that were compromised by the siege of the shieldhall months earlier had been repaired as best as they could. Civilians and noncombatants were kept in the shieldhall's basement, where they had been kept safe during the siege. The defenders also made use of the lessons learned during their nearly failed defense, creating more fallback positions should any one gate be overrun and demolishing and booby trapping buildings near the northern gate to reduce the amout of entry points the attackers had. The defenses here were mostly organized by the Hellrider Kaiden Miursa.
Shiarra's Market, though not a traditionally fortified structure like the shieldhall or High Hall, had nonetheless been turned into a veritable fort through the efforts of Klav Ikaia, who oversaw its defenses. The civilians of the market were led into the city's underground Maze, with passageways blocked off via controlled demolitions that turned the tunnels into bunkers. The buildings around the open air market were demolished or used for defensive materials, and entranceways into the market were reduced to better funnel attackers into the blades and fangs of the defenders, both living and undead.
The forces of the Abyss were camped on the Disward side of the River Styx in massive, horizon-spanning warcamps that contained little order or discipline. The forces were a mix of demons and gnolls, and were only kept contained through the sheer power and presence of Yeenoghu, who personally came to oversee the battle.
However, the Yeenoghu's forces did already have a forward operating base in the Elturian docks, just south of Shiarra's Market, which had become so fortified that it was near impossible to dislodge. Such a base allowed the demons to easily strike at the Elturians once the battle began.
The forces of the Nine Hells were camped on the Contra-Dis side of the Styx, though bridges and ferries had already been constructed to allow for quick access to the opposite shore. However, no move was made to establish large camps or defenses on the far shore, as the infernal command believed that doing so would preemptively trigger the demons' attack. The forces of Hell were led by Archduke of Avernus Zariel, who was stationed in her flying fortress, by which she could issue orders to her subordinates and oversee the entire battle.
Though these were the major areas of preperation, there was an additional planned deployment. The Lost Star Detectives gathered at High Hall with the aim of flying above the government complex to the floating debris surrounding the Companion. Their goal was to unlock the Companion with a set of keys they had retrieved while in Avernus, freeing the solar inside and reversing the device's charge to allow for the Companion to send the entire city back into the Material Plane. Doing so would likely draw Zariel's best soldiers and even potentially Zariel herself, which the Detectives were counting on, as they had retrieved the Sword of Zariel as well, which contained a spark of Zariel's pre-infernal essence and could allow them to redeem the once-angel, thus nullifying her contract binding the city. If that were to fail, then the Detectives planned to take Zariel's half of the contract by guile or force, thus allowing the city to be saved.

Battlefield

The multiple deployment zones of the battle also necessitated multiple battlefields.
Numbers wise, the vast majority of the combatants fought on the open plain of Avernus, throwing infernal warmachines and other weapons of war at each other while clashing on relatively open, craggy fields.
By contrast, the terrain of Elturel was treacherous following months trapped on the plane of Avernus. Many buildings had been intentionally or unintentionally demolished, streets were transformed into barricaded corridors, sections of the Maze were collapsed, and large swaths of Elturel were entirely abandoned for more defensible areas.
Additionally, the battle's critical fight around the Companion would take place on the debris floating around the artificial sun. The debris had initially been thrown into the air when a stray meteorite hit High Hall during the early days of the Elturel's damnation and it was held in stasis in the air by the magic surrounding the Companion. The fighting there would be precarious, balanced on terrain hundreds of feet in the area, above the defenders of High Hall.

The Engagement

The battle began upon the unlocking and opening of the Companion by the Lost Star Detectives, freeing the solar Nascius inside. Nascius, gratefully freed, promised to remain within the Companion and use his celestial energy to build up enough of a charge for the Companion to teleport Elturel back to the Material Plane. Doing so resulted in the Blood Legions beginning to move, with Zariel ordering her trusted elites to defend the Companion and prevent its repurposing, which in turn prompted the armies of the Abyss to rush forward and stop their infernal rivals.
While the bulk of the demonic force was stymied by the Blood Legions of Hell, more than a few demons and gnolls broke through the devil's rigid defense of Elturel, swarming into the city, searching for mortals to kill. Many of the noncombatants that refused to take shelter in one of the four safe zones were found and butchered, but the demons very quickly located the four strongholds within the city.
The first to be attacked was Shiarra's Market, as a demonic stronghold in the docks had not be uprooted in the preceeding months, growing in strength and bidding its time. Helm's Shieldhall, High Hall, and Maiden's Leap were attacked in turn, as waves and waves of demons and gnolls attempted to break through each area's defenses and slaughter the Elturians within.
As the fighting increased on the ground, the Lost Star Detectives were confronted by a force of devils, led by Olanthius and Haruman, Zariel's two most trusted aides. The forces of Zariel also brought with them the pitiful infernal soul of Xifira Mistmore, a Detective who had died during their journey, who they hoped to use as a bargaining chip. The Detectives battled the devils fiercely, and during the course of the fighting, Xifira's soul was destroyed by Kinsey Eridanus, who did not recognize her friend in life. During the course of the fierce fighting, the Detectives were nearly wiped out until Katya Sinaran chose to abandon her worship of Kiaransalee for good and prayed to an emblem of Torm and Bahamut for aid. The gods answered Katya's call, and Torm healed all of the Detectives' wounds to keep them fighting while Bahamut sent a copper dragon agent of his, Burney, to aid in their fight. Burney quickly helped the Detectives before flying off to attack the demons swarming into the city, slowing down their assault.
With renewed strength, the Detectives slew Haruman, angering Zariel and drawing her to the Companion to end things personally. Upon her arrival, Zariel demanded her former sword  which was in the possession of Alesine Zadava. Alesine agreed to turn it over, trusting that the spark of Zariel's celestial nature inside will allow the archdevil to redeem herself.
Upon grabbing the sword, Zariel and all of the Detectives were brought to a shared memory of the moment Zariel chose to fall and become a devil after the Charge of the Hellriders. Each of the Detectives and the hollyphant Lulu, Zariel's closest companion as an angel, implored to make a different choice, that she didn't have to be defined by her past, and that all this suffering isn't worth it. With their encouragement, Zariel seized her sword and took up the mantle of an angel again.
No longer a devil, Zariel released Olanthius from her service, who passed peacefully to his destined afterlife in Mount Celestia, and she flew off to engage the demon horde swaming into Elturel. Her defection also nullified the pact holding Elturel in Avernus, and thereby released the chains binding the city. All that was left to do was to wait for the Companion to build up enough of a charge to teleport the city back to the Material Plane.
Disordered by the defection of their commander, the forces of Hell began to waver and Yeenoghu's horde pressed its advantage. No longer needed at the Companion, as it wasn't under any pressing threat, the Detectives then split up. Kinsey, Katya, Whisk, and Lulu flew to Shiarra's Market, where Kinsey's parents were, to aid in its defense. Meanwhile, Arcus Miursa, Dzarya, and Alesine flew to High Hall, holding the line with the other defenders while the Companion slowly continued its charging.
Finally, as the defenders of Elturel were pushed to the breaking point and the demonic tide appeared to be too much, Nascius finished his work charging the Companion, and the entire city and everything on it was teleported back to the Material Plane.

Outcome

Upon Elturel's planar teleportation, the gods Torm, Helm, and Lathander created a pocket dimensional space that allowed Zariel to talk with the Detectives before their arrival back on the Material Plane. During their conversation, Zariel, with Lathander's aid, forsook her celestial nature, feeling herself unworthy of it, and bestowed it upon Alesine Zadava at Lulu's suggestion, turning Zariel into an unaging mortal and Alesine into a solar.
Now that Elturel was no longer blocked by the veil of Hell, the gods were also able to use the celestial energy of the Companion to eradicate all the demons and devils present in the city when it was transported, while most of the gnolls were captured and killed by various powerful magic users that were summoned by Sylvira Savikas, who was warned by the Detectives that the city would be reappearing soon. The gnolls that weren't killed fled into the wilderness. The dragon Burney also flew off following the battle.
In Avernus, the forces of Hell continued to clash with the forces of the Abyss. Despite the loss of a large portion of his army when Elturel disappeared, Yeenoghu nevertheless held the upperhand following Zariel's defection. It was only after many of the forces of Hell were rallied by the archdevil Gargauth that the the demons were forced to fall back, albeit after inflicting heavy casualties.

Aftermath

The Battle of Elturel marked and end to the city's damnation, but the effects of the battle would shape Elturel and the surrounding Western Heartlands for decades to come.
Despite Elturel's reappearance, the nation of Elturgard still fractured back into the city-states it was formed from, and Elturel lacked the power or influence to hold the nation together by force.
Elturel's salvation also prompted the beginning of its succession crisis, namely between Klav Ikaia and Alcor Miursa, the father of Arcus and Kaiden Miursa that had been in infernal captivity before being released by Zariel as one of her last actions as archduke. Ikaia had the backing of his dhampir forces while Miursa was the chosen leader for the remaining Hellriders and the Order of the Sun, whose planned attack against Ikaia was delayed due to their heavy casualties in the battle. Ultimately, with the support of the Detectives, the angel Alesine, and Zariel, Ikaia fled from the city with his forces, either unwilling or believing himself unable to take the reigns of power by force. Alcor Miursa was proclaimed the city's new High Rider.
In addition to using the term High Rider over High Observer, nearly all cultural elements of Elturel over the past fifty years became anathema for Elturians. As the city began its long process of rebuilding, areas named for and after the founders of Elturgard were renamed after the saviors of the city, such as Maiden's Leap, which was renamed Enki's Rest after the ki-rin that settled there.
Ikaia's survival resulted in the establishment of the Order of the Sun from an anti-vampire coalition into a fully fledged, militant sect of Kelemvor, as the order's patrols to find and hunt down Ikaia transformed over time into regular patrols to seek and destroy and undead presence.
The survival of Ulder Ravengard also allowed him to return to Baldur's Gate, where he was again given the title of Grand Duke, resuming his control over the city.
Their work done, the Lost Star Detectives disbanded after the battle, though nearly all stayed for some time to help with rebuilding Elturel. Alesine Zadava, aware that her celestial power was too much to keep on the Material Plane, departed for Mt. Celestia. Katya, Kinsey, and Arcus remained in Elturel in the short term, while Whisk and Dzarya took to interplanar traveling. Lulu split her time between Alesine in Heaven and Zariel, who had decided to seek penance by wandering anonymously around Toril.
Gargauth's rallying of the forces of Hell against Yeenoghu following the battle put him on the path to become the next archduke of Avernus, a title he had held nearly a milennia previously.

Historical Significance

A strong proponent of history and truth, Alesine Zadava made sure before departing that the true facts of the Battle of Elturel were recorded before she departed in order to prevent the facts from being altered by those seeking political gain. Because of this, the journey of the Lost Star Detectives and the details of the Battle of Elturel have remained firmly rooted in fact in official histories, though unsuprisingly that has not stopped folk retellings of the battle from exaggerating events or shifting around details for a better story.

Legacy

The Battle of Elturel cemented the status of the Lost Star Detectives as modern mythical heroes, and the redemption of Zariel at their hand and the subsequent ascension of Aleisne Zadava from mortal to angel, captured the imaginations of all who heard their story. The battle would also help each Detective in pursuing their individual goals later in life, whether that be finding their place as an angel of Lathander, joining the Emerald Enclave, aiding the Sha'sal Khou, or settling down for a quiet life of peace.
Combatants in the battle would also continue shaping the history of Elturel for decades to come, such as Thei Linden, whose actions in the battle would ultimately propell him to become Alcor Miursa's successor as High Rider of Elturel.
Zariel's redemption also spread like wildfire among the planes of existence. As the highest profile archdevil to both fall and rise, her story served as a beacon of hope for all the forces of good across the many planes and as a dramatic climax of the story of her life, though she of course continued living on in obscurity for long after the battle was over.
Gargauth's role in rallying Hell against Yeenoghu also lead to his second tenure as archduke of Avernus. How long that reign will last remains to be seen.
The Battle of Elturel and the ultimate salvation of the city also put to rights the story of the Charge of the Hellriders, which for centuries had been misremembered. With the Detectives aid, Olanthius and Yael were reremembered for their actual deeds, and the name Hellrider again carried with it glorious weight and purpose. Though the mythical tale of the charge was still a popular story, the myth would never again obscure the true facts of that battle.

Included under Conflict

Damnation of Elturel

Conflict Type

Battle

Battlefield Type

Urban

Start Date

2nd of Tarsakh

Ending Date

30th of Tarsakh

Conflict Result

Elturel saved from damnation; Crushing loss for the forces of Hell; Acceptable outcome for Yeenoghu's horde.

Location

Elturel

Belligerents

Defenders of Elturel

• Flaming Fist
• Hellriders
• Lost Star Detectives
• Order of the Sun

Led by

• Alesine Zadava
• Arcus Miursa
• Dzarya
• Kaiden Miursa
• Katya Sinaran
• Kinsey Eridanus
• Klav Ikaia
• Niri Whistlewood
• Thei Linden
• Ulder Ravengard
• Whisk

Strength

• The Lost Star Detectives
• The mortal and dhampir defenders of Shiarra's Market
• The Hellriders and Flaming Fist of High Hall
• The Hellriders and Order of the Sun defenders of Maiden's Leap
• The Hellrider defenders of Helm's Shieldhall
• One copper dragon
• One ki-rin

Casualties

• Heavy casualties at Helm's Shieldhall and Maiden's Leap
• Moderate casualties at High Hall and Shiarra's Market

Objectives

Hold out for enough time for the Lost Star Detectives to destroy the pact binding the city and for the Companion to charge enough to teleport Elturel back to the Material Plane.

Yeenoghu's Horde

Led by

• Yeenoghu

Strength

• Near uncountable number of gnolls and demons

Casualties

• Heavy casualties in the fighting around Elturel
• Complete annihilation of all demons within Elturel

Objectives

Destroy Elturel and all within it before the city is sunk into the Styx, thereby denying more souls to the Blood Legions.

Zariel's Blood Legion

Led by

• Zariel

Strength

• Near uncountable number of devils

Casualties

• Heavy casualties in the fighting around Elturel
• Death of Olanthius and Haruman 
• Defection of Zariel to the Defenders of Elturel

Objectives

Prevent the forces of the Abyss from destroying Elturel and stop the defenders of Elturel from undoing the city's damnation.