Blood War

The Blood War was an ancient conflict that raged between the fiends of the Lower planes. The two main sides of the war were the demons, inhabitants of the evil plane of chaos of the Abyss; and devils, representing the equally evil but lawful realm of the Nine Hells. Neutral evil yugoloths played both sides against one another. The Blood War had raged on since the Age Before Ages, a dark time when the Prime Material Plane had not fully developed. The conflict was massive, spanning entire planes of reality and hosting an almost infinite number of fiends.
==Location==
The majority of conflicts in the Blood War took place in Avernus, the first layer of the Nine Hells. Demonic forces sailed the River Styx into Avernus and were repelled by infernal legions that brought reinforcements from the lower layers of the Hells. The conflict, however, often did not remain confined to Avernus, as destructive skirmishes emerged anywhere in the multiverse where demons and devils could appear.
Another important battlefield of the Blood War was Oinos, the first layer of Hades. Battles occasionally leaked to the deeper layers of Niflheim and Pluton.
The Blood Rift, an endless river of blood that wound through the planes, passed through both Avernus and various planes of the Abyss, such as the Barrens of Doom and Despair. This unique formation granted yet another passageway for demons into the first layer of the Nine Hells. Conversely, it also allowed battles between the fiends to spill out across the Barrens.
In the demonic front, Pazunia was one of the primary battlegrounds. Devils often attempted to conquer the first layer of the Abyss in the hope of controlling the entire plane.
At least on one occasion, the Blood War extended into the upper planes, spilling into the Beastlands by means of an open portal.
==History==
===Causes===
The cause of the Blood War was unknown, but most believed it to be a remnant of the great war of Law against Chaos waged by the Wind Dukes of Aaqa against the forces of the Queen of Chaos. The yugoloths liked to entertain the notion that the War was their own personal experiment into the nature of evil, one which they created and would ultimately end on their own terms. 
Some philosophers speculated that the Sigil's Lady of Pain had something to do with the Blood War, but what connection she actually had was not clear.
Yet another theory involved the origin-myth of Asmodeus, in which he was an angel who traveled into the heart of the Abyss and plucked a single shard from the "seed of evil." It was said that Asmodeus foresaw his own victory in the conflict―a definitive triumph of law over chaos―and believed that he would subsequently unite all the planes of law under his singular rule.
Some sages posited that the Blood War was a simple offshoot of the primordial wars between law and chaos. The lawful good-aligned celestial archons and chaotic good-aligned eladrin only marginally participated in the conflict, mostly ensuring that the battle remained confined to the lower planes. The demons and devils (in keeping with their sadistic and violent natures) simply would not cease their fight, even after the rest of the multiverse had grown more tolerant.
===Motivations===
The devils of the Nine Hells held the belief that they served as the first bulwark against the destructiveness of demonkind, which threatened all of existence. To them, the fate of the multiverse rested on their capacity to contain demons within the Abyss. They also used the conflict as an opportunity to harvest souls for their superiors in exchange for boons. Souls taken in this way could be stored in small trinkets called soul coins and used to power the war machines of the Nine Hells.
While some scholars speculated that demons merely fought in the Blood War because they were mindless entities of destruction, there was more ingenuity to their involvement. Although most demon lords had little direct involvement with the conflict, it provided the ideal distraction for them to carry out their malevolent machinations (often against one another) and demonstrate their superiority over the rest of the cosmos.
Many lesser fiends actually embraced the War, for it staved away the cosmic boredom of being ageless. A few races survived on the carnage the Blood War produced; the armanites, centaur-like tanar'ri, must constantly battle with other creatures, for otherwise they would turn on one another; the molydei were another race of demons who prowled the Abyss, searching for deserters or rogue demons they could press-gang into fighting. 
The Blood War gave way to other terrifying constructs of war, such as the massive hellfire engines that were used to mow down waves and waves of demons. In fact, certain creatures such as the bulezau were bred by other fiends exclusively for the Blood War.
Even the yugoloths were given purpose by the Blood War; forever shifting from one side to the other, they as a race gained much of their wealth and power from the spoils of war and the high price of their services, though some―including the yugoloths themselves―believed this to be simply a façade to hide older and darker motivations.
===The Battle Begins===
While it was unknown exactly when the first battles of the Blood War were fought, it was believed by scholars to have begun some time following the Dawn War, the conflict between the gods and primordials. One account states that a band of baatezu explorers went out traveling the planes, and upon their first encounter with the tanar'ri, got into a heated philosophical debate that led to violence. With each group of fiends knowledgeable about the other, they dispatched raiding parties against the other, and small skirmishes broke out across the planes.
In the early centuries of the Blood War, advantage in the conflict shifted wildly between the devils' and demons' favor. Control over planes of Carceri and Gehenna changed repeatedly over the course of mere years. Some yugoloths joined either faction of the war, and expectedly in their first battle, betrayed their patrons for the opposing side. Over time, the balance of the war appeared to to shift less and less, until a strange sort of balance formed between the two adversaries.
===Celestial Influence===
Each side of the war began to explore the cosmos beyond the lower planes, and look for alternate routes to strike out against their foes. They began to maneuver through the River Styx, and even Yggdrasil the World Tree, to extend the Blood War into the greater multiverse. This expansion of hostilities elicited a swift and authoritative response from the celestials of the upper planes. They struck down indiscriminately against the fiends, slaying devil and demon alike, until the tide of war turned. For a brief few days, the baatezu and tanar'ri ceased hostilities with each other, and struck out against the forces of Celestia.
It became apparent that the celestial beings of the Upper Planes, formidable as they were, could face destruction at the hands of the tanar'ri or the baatezu. Weighed down by their alignments demand by the needs of good and justice—the fiends, having no such compunctions or scruples, easily manipulated the celestials' morality against them. Within a week of entering the conflict, the celestials were turned away by the combined fiendish horde. According to some accounts, only three thousand of the angelic beings survived.
After some heated debate about which side to strike out against during the next assault, the celestials eventually entered into an agreement to abstain from fighting for, or against, either side of the conflict. Their influence in the conflict there, had to be more discreet. On some occasions, agents of the heavenly races planted powerful weapons or artifacts among the ranks of the demons or the devils. This appeared to be a reliable indicator that even the beings of the Upper Planes did not want the war to end.
Some time after the fiends of the lower planes became aware of―and then recruited―powerful entities known as deities, they each discovered new, unwilling soldiers for their escalating war: petitioners, the souls of deceased mortals that appeared in the lower planes. The Baatezu discovered they could manipulate and warp these souls to form new, lesser fiends, and the secrets of the twisted practice later leaked to the tanar'ri.
It was some time later that the fiends of the lower planes came to understand they could recruit mortals directly from the Prime Material plane. Once again, each side acted in kind, seducing, coercing, or otherwise manipulating individuals from various worlds to serve as pawns in the endless war against their collective foe. The introduction of mortal blood into fiendish warfare led to the creation of new breeds of devils and demons, as fiends of all sorts crossbred with the mortals of the Prime. The first cambions, alu-fiends, and tieflings were thus born into existence.
===Endless Warfare===
Fighting between the fiends continued on for millennia. Throughout all the battles and constant strife, no side had been able to gain even a definitive, permanent advantage over the other. Despite their vast differences, the tanar'ri and the baatezu were surprisingly balanced combatants. Once one side gained the upper hand in the conflict, the other took advantage of a weakness on another front of the war.
The chaotic denizens of the Abyss, while far more numerous than the devils, were, true to their alignment, constantly warring amongst themselves. They could contest the might of the Nine Hells only through sheer individual power, and their seemingly limitless, if unorganized and uncoordinated supply of warriors. The baatezu, on the other hand, deployed smaller numbers onto the field, but their warriors were regimented, well-trained and well-disciplined, all the while making incredible use of their generals' ruthless strategies. This violent balance could have kept the Blood War fueled for an indefinite period of time.
At some point in history, the Blood War temporarily ceased in response to the emerging threat of the great illithid empire. The illithids had conquered both the Astral and Ethereal planes and threatened the Outer Planes themselves.
One thing, however, was certain: had one side been able to eliminate all opposition and thus gain control over the entirety of the Lower Planes, the multiverse as a whole would have been in great danger. With no enemies left in the Lower Planes, the fiendish rulers could then have turned their attentions towards other worlds and planes, and it was likely that no force could have hoped to stop them. 
===Armistice===
There was a prophecy that said that the Blood War would end when the Crawling City, a city on the plane of Gehenna that was home to millions of yugoloths, directly entered the Blood War.
However, once Asmodeus regained his divinity by absorbing the divine power of Azuth, he professedly ended the Blood War by pushing the Abyss to the bottom of the Elemental Chaos in the World Axis cosmology. 
Thus, for the inhabitants of Realmspace, the seemingly eternal Blood War finally came to an end at the hands of the deified archdevil Asmodeus, with the devils thus victorious in a manner of speaking. However, this apparent victory was regarded across the multiverse as no more than an uneasy truce. Demons, scattered and consumed by infighting, could not muster the strength to resume the conflict, whereas devils kept themselves busy with strengthening their own realms, aware that an assault on the Abyss could be the pretext to unify the demon lords against them. 
In fact, observers across the multiverse reported that the conflict continued elsewhere, as both forces were forever kept in check and balanced despite temporary advances or apparent victories from either side. For some time, mortal worlds on the prime Material plane became the sites where demons and devils struck out at each other.
===Restarting Hostilities===
Despite Asmodeus' claims, the denizens of the Nine Hells knew that throwing the Abyss into the Elemental Chaos did not stop the Blood War, but only stalled it on Toril for about a century. By the Faerûnian year 1486 DR, the demons had mustered enough forces that many devils feared the war would begin again. Asmodeus remained unable to intervene, as he was indisposed dealing with the emerging events of the Second Sundering on Toril.
In spite of the cessation of the Blood War, a proxy conflict arose on Toril during the First Tymanther-Unther War. While on the world of Abeir, the god-king Gilgeam contacted the demon lord Graz'zt and asked him to aid Unther in their war against the genasi forces of Shyr. On Nightal 26 1486 DR, Unther was returned to Toril as part of the Second Sundering, and Gilgeam immediately moved against Tymanther to reclaim the former lands of Unther from the dragonborn.
On Hammer 10 of 1487 DR, the forces of Gilgeam laid siege to Djerad Thymar while the Chosen of the gods Asmodeus and Azuth conducted a ritual on the city in order to make both gods separate entities again. To maintain her position in the Nine Hells, Glasya sent the Malbolgean forces, led by a pit fiend named Khartach, to help the Thymari against the demons, helping the Chosen to accomplish their goal.
By the , the Blood War was raging in full force on the battlefield of Avernus. The archdevil Zariel began plucking cities from the world of Toril, using their citizens as fodder against the demonic hordes. 
That year a massive horde of demons appeared on Avernus, one that could overwhelm the baatezu defenders that stood in their way. It was believed that a tanar'ri victory in that battle, could shift the balance of the Blood War, and grant the demonic hordes opportunity to run rampant across other planes of existence.
===Effects===
The Blood War left the planes that served as its battlegrounds permanently scarred, warped by the endless warfare that was raged across their landscapes. Over millennia, the paradise of Avernus of transformed into a deformed wasteland, where fiery stones rained from the skies. The Iron Wastes in the Abyss were scattered with ruined outposts that dotted the surrounding desolation. The blasted battlefields led to the spawning of horrific viper trees, where alluring fauna once flourished.
Some academics of interplanar affairs believe the Blood War was actually the most preferable outcome, to one of the three that could arise from the conflict between devils and demons. Their constant warring placed the Lower Planes in a twisted form of equilibrium, a Balance that―according to some―had to be maintained at all costs, for if one side of the Blood War were to emerge victorious, surely that victor would become a threat to other planes of the multiverse. 
==Combatants==
The greatest powers of the Nine Hells and the Abyss did not take an active role in the Blood War. The sole exception was whoever served as the Lord of Avernus in the Hells.
The mightiest demon princes, such as Graz'zt, Orcus, and Demogorgon, were constantly at war with each other within the Abyss, and at times had little concern for the Nine Hells.
====Baatezu====
The Dark Eight were a coven of pit fiend generals who resided in the Ninth Layer of Hell, Nessus. They plotted and strategized the movements of Hell's armies. They had strong ties to Bel, the one-time Lord of Avernus. Their relationship kept the relatively weak Bel safe from the other archdukes of Hell. He remained Lord of the First until he in turn was ousted by Zariel, reduced to serving as her lieutenant.
Zariel herself was conscripted to the Blood War after being brought before Asmodeus. As a solar of Mount Celestia, Zariel ignored the orders of her superiors and led a group of mortal warriors into Avernus to join the Blood War. Her forces crumbled when faced with the horrors of the Hells, and Zariel was captured and sent to Nessus. Asmodeus was so impressed with her zeal for warfare, he offered her the legions of Hell to command against the endless hordes of demonic invaders.
Duke Bael served as a general of Mammon in the Blood War, winning many victories and exaltation for himself.
Each layer of the Nine Hells, save for Nessus, was forced to muster its own legion to fight for their cause in the Blood War.
====Tanar'ri====
Baltazo, a grotesque minor demon lord, was also a mighty general in the Blood War, but had since retired to the Plain of Infinite Portals.
Eltab, was one demon lord that won many battles―and garnered much glory for himself―in the Blood War.
The Demon Queen Lolth had some unknown involvement in the Blood War, employing spies on the plane of Avernus.
====Other Combatants====
The ultroloth Mydianchlarus led denizens of the Blood Right in some of the most horrific battles of the Blood War, but was eventually deposed by one of his lieutenants.
==Appendix==
===Appearances===
:;Adventures
::Baldur's Gate: Descent into Avernus
:;Novels
::
::Fire in the Blood
:;Comics
::Infernal Tides 
:;Organized Play & Licensed Adventures
::Avernus Rising (Escape from Elturgard • Faces of Fortune • Infernal Insurgency • The Diabolical Dive • In the Garden of Evil • Tipping the Scales • Losing Fai • Fang and Claw • Where Devils Fear to Tread • Hellfire Requiem
===Gallery===
blood war-4e.jpg|A balor and a pit fiend dueling.
blood war poster-2e.jpg|A baatezu enlistment poster.
Bloodscuffle.png|A legion of devils comes across an infighting demon mob.
===References===
pt-br:Guerra do Sangue
Category:Wars
Category:Events in the Upper Planes
Category:Events in the Beastlands (plane)
Category:Events in the Lower Planes
Category:Events in the Abyss
Category:Events in Carceri
Category:Events in Gehenna
Category:Events in the Nine Hells
Category:Events in Avernus
Category:Events in Hades
Category:Events in Oinos
Category:Events on the River Styx
Category:Events in the Plain of Infinite Portals