Following The Great Treachery, the Imperium was in shambles, its leaders were broken, many of its planets were desolate ruins, and its armies were shambling fragments of their former glory. While many of its leaders wanted to go on one final suicide charge of vengence into the eye of Terror, Constantine Valdor and the High Lords of Terra ultimately ordered a respite from the conquest. While The Emperor was alive (albeit gravely wounded), his dream of the great crusade was dead. Now if Humanity was to survive it must reorganize itself so that it could rebuild its strength and bide its time, awaiting the emperor to return. Thus the Council of Terra was called, hoping to forge the Imperium into a permanent political force that could avoid the events of The Great Treachery.
The Calling of The Council of Terra:There was no guarantee that such a council was going to be called, and in the aftermath of The Desolation of Lorgar, that the Imperium could survive at all. True, Sanguinius was able to wrest victory from the jaws of defeat, but for many it felt more akin to a stay of execution.
Primarchs at The Council of TerraVery few of the Primarchs escaped the Treachery of Lorgar Unscathed. So when the Primarchs arrived at the Council of Terra, none saw themselves the same as when they started.
Horus (present, favored moderate reform)Horus's attempts to coordinate military matters during The Great Treachery were severely hampered by an attempted mutiny of Horus Aximand, who was corrupted by The Anatheme Blade. The aftermath of said mutiny was Horus gathering up and executing each and every one of the traitors (including "Little Horus" personally). Horus still bears the physical and emotional scars of this incident, but didn't blame himself as Dorn and Russ did. Instead he blamed his Father, The Emperor, for failing to inform him or his brothers about the dangers of Chaos, resulting in the Legions being completely blindsided by The Treachery. In particular he blamed the death of Horus Aximand and most of the Mournival on the Emperor, believing that he could have saved his wayward son had he known about the corruption festering within him. While still a believer in the Crusade, and his father's dream, he was much more open to the suggestions of his more unorthodox brothers.
Dorn (absent)Rogal Dorn took the Injury of his Father very personally. Rogal was not seen again until several Millennia later. Instead The First Captain of The Imperial Fists arrived at the Council of Terra to deliver Rogal Dorn's resignation as Praetorian of Terra and announcement of self-imposed exile.
Magnus (present, favored heavy reforms)Perhaps the one who suffered the most out of The Great Treachery, losing his homeworld, and most of his legion to The Space Wolves. Magnus sought a complete reversal of the Council of Nikea, as well as several other reforms. While loyal to The Emperor, he saught a dismantling of the Imperial Truth, which he saw as a failed Noble Lie and blamed it for the destruction of Prospero.
Leman Russ (present, neutral)The Lone Wolf, now without a Legion. Russ shouldered the blame for the fall of the Space Wolves. Leman still believed in The Emperor, but everything else was shaken. He went into the Council to make ammends for Prospero and planned to support any initiatives brought forth by Magnus. While he did not disparage the Imperial Truth as Magnus and Khan did, he questioned its ability to actually protect the Imperium from the Forces of Chaos.
Lion El'Johnson (present, leader of status-quo faction)Entering Terra with Half of his legion missing, The Lion was still a steadfast believer in The Imperial Truth, but also understood the viewpoints of its detractors. Apart from greater initiatives for counter-intelligence, The Lion simply wanted the Imperium back on its feet as quickly as possible so that he could rebuild Calliban and hunt for The Fallen.
Jaghatai Khan (present, leader of reform faction)Jaghatai and Magnus were the two Primarchs who entered with an agenda for an overhaul of The Imperium. Like Magnus, Jaghatai had also disparaged the Imperial Truth, and sought to have both it and The Council of Nikea overturned. He also planned to use the death of Roboute Gulliman and tenuous state of Ultramar, the Draft of The Codex Astartes, and its Fledgling Aurelian Cult to his advantage. Khan hoped to see the Imperium transition from a collection of armies led by Terra to a more nomadic court of galaxy faring Tribes similar to his Homeworld of Chorgoris. He saw the Legions divided into bands of quasi-independent tribes led by a Qagan (the Primarch), who would spread across the galaxy providing protection for the subject planets who would provide men, tithes and culture. Much of this vision was instilled into "Roboute Gulliman's" Codex Astartes .
Konrad Curze (present, neutral)Perhaps the only man present whose outlook on the current state of the Imperium improved following The Great Treachery. Konrad Curze was still plagued by visions of the worst that could happen to the Imperium, but noticed that his visions had become significantly less horrible, which indicated to him that The Imperium was spared some great tragedy. The sight of The Shadow Raven and "looting" of Nostromo by the Iron Warriors forced the Night Haunter into some introspection. His outlook was similar to Horus in that he felt betrayed by his Father's lies, but took comfort in the fact that this grief was shared (he also enjoyed the death of his brothers' insufferable optimism).
Corvus Corax (MIA)No one had seen or heard from Corax, or his Legion. Curze assumed the worst, but those closest to the Raven Lord: Vulkan and Russ refused to believe he had betrayed them. They couldn't help but wonder though, and his absence was yet another death-knell for The Imperial Truth.
Roboute Gulliman (KIA)Wasn't able to attend on account of being dead. Instead Khan insisted on bringing Chapter Master Antolli and The Captain of The Maccragge Migrant fleet to speak on their Father and Lord's behalf.
Sanguinius (chair, favored reform)Sanguinius simply wanted to have things return to normal, but as it became clear this was no longer possible, Sanguinius tried to balance what he thought would make a strong imperium with the concerns of his brothers.
Decision:The Fate of The ImperiumGiven the state of Weakness of their Father, it was decided that the Primarchs would govern the Imperium in their father's stead. The Primarchs determined the best course of action would be to create a quasi decentralized system, where certain primarchs would take command of the outer segmentums, while other primarchs remained on terra to manage the Imperium at Large. The Primarchs would also oversee the fledgling Human Government which would maintain its limited power.
Descisions:The Emperor would officially remain the head of the Imperium
De Facto governance of the Imperium would be done by "The Regent Consuls"
The Primarchs would all share equal authority when acting as "The Council of Regents"
Regent CouncilsSanguinius was chosen to be The "Warmaster" and Co-Consul of the Imperium.
The Regent would act in the Emperor's stead and oversee the overall management of the imperium, as well as serve as head of state for diplomatic dealings.
Sanguinius would be "First among Equals" and would act as the Chairman of the Council of Regents.
Sanguinius would oversee the High Lords of Terra as a stand-in for the Emperor
Horus would remain "Legiarch" and Co-Consul
Horus would overrule Sanguinius on all matters pertaining to war.
During war councils and coordination of the Legions, Horus would be First Among Equals
Half of all Imperial Tithes would be granted to Horus to use as he saw appropriate for The Imperium's Defense.
The High Lords of Terra
The High Lords of Terra would remain as governors of the Day-to-Day Management of the Imperium
The Segmentum Solar would remain under their control
As of the Council of Terra, Segmentum Tempestus was kept under the control of the Council until Dorn took command of it in M31.
Sanguinius, acting in stead of his Father, would oversee the High Lords and could overrule them as he saw fit.
The Realm of Ultramar would be granted a seat on the High Lords of Terra
Malcador's Inquisition would also be granted a seat on The High Lords of Terra
An additional seat would be created "Administratum Fidelarum" this position would be chosen jointly by all of the accepted religions in the Imperium.
This was a compromise from Jaghatai Khan's desire that each religion be granted a seat
At-Large Primarchs:
Several of the Most Capable Primarchs would act in service to the greater imperium.
Per his request, Leman Russ was relieved of all duties, but he still officially has a seat on the Council
These Primarchs included:
Magnuswho would oversee the Golden Throne and oversee all psyker related activities
Konrad CurzeWho would take over Leman Russ' Role as "The Emperor's Executioner,"
Konrad Curze also served as the Council's "liason" to The Imperial Inquisition
FulgrimWho was given oversight over all genetic, medical, ecological, and terraforming operations
Ferrus ManusWho Oversaw engineering and technological projects
Dorn (nominally)Dorn remained officially the Praetor of the Imperium, until he was later given the Segmentum Tempestus. As of the 41st Millenium this office was left vacant. Curze, Magnus, and The Custodes all perform the basic functions of this office to protect the Emperor.
KhanKhan oversaw the Free Chapters of Astartes, effectively making him Liaison to Ultramar, Grandmaster of The Grey Knights, and Head of Internal Security.
Segmentum PrimarchsSeveral of the Most at risk Segmentums were granted to the remaining Primarchs.
The Primarchs were permitted to govern these segmentums as they saw fit, and could only be overruled by the Council of Regents.
The Lion (Obscura), Vulkan (Pacificus), and Later Dorn (Tempestus) were granted segmentums in which they would rule.
Decision:The Fate of The LegionsEach Legion and Primarch was thoroughly investigated by Constantine Valdor and The High Lords of Terra to determine if The Legion was still capable of serving the Imperium.
Ist LegionThe Dark Angels were under intense scrutiny following the Great Treachery due to the sheer number of traitors who had joined Luther's cause. This was made only worse by the Lion's hostility to both Valdor's Investigation. Partially because of his own distrustful personality, partially because he thought these investigations were a waste of time and impeded his hunt for Luther, and partially out of contempt for the High Lords and Valdor. It took the cajoling of his brothers Horus and Sanguinius to convince him to cooperate. When he finally did, most of the vestigial influence of Luther was removed and it was determined that his Legion was sufficiently Loyal.
III LegionThe Emperor's Children for all intents and purposes, did not exist. However Fulgrim himself had to submit to investigation due to account on the Laer. Fearing this race were devotees of Slaanesh, Fulgrim's life and health had to be thoroughly examined. When the all were satisfied he was cleared of any wrong doing, the Legion was considered to be Dismantled until the issues with his geneseed could be resolved.
IVth LegionThe Iron Warriors, like the Death Guard, was a legion already rife with division before the war even began. Unlike the Death Guard, Perturabo's Legion was mostly purged of any detractors before the heresy began. With many being sent to the frontlines of his bloody seiges. There was not enough to rebuild a legion, and so the remaining members were permitted to form Chapters.
Vth LegionGiven that White Scars Primarch, Jaghatai Khan, was indirectly responsible for both the Demon incursion on Monarchia and the Death and Apotheosis of Roboute Guilliman, the Judges were very interested in The Khan's activities both during Monarchia as well as his and Magnus' escape from the Warp. Making things more complicated were his loyaties to ancient Terran religions and general sympathy for faith. His legion was found to be thouroughly loyal if perhaps a bit too esoteric, and was permitted to continue.
VIth LegionThere were many who wished to see The Space Wolves returned. Magnus and Fulgrim speculated that the problems with the Wulfen were more the result of Canis Helix on Fenris than the Russ himself, and could be resolved. However it was Leman Russ who pleaded for the dissolution of his legion. The Judges Acquiesced. Those few wolves that remained were organized into penitent chapters, the only loyalist legions required to do so.
VIIth LegionVery few of The Judges doubted the Loyalty of The Imperial Fists. However they were irritated in Rogal Dorn's decision to abdicate and go on a penitent crusade of one. Once it was determined that this self-imposed exile was out of grief rather than corruption, the Imperial Fists were allowed to remain intact. Sigismund, Champion of the Imperial Fists was made Commander of the Legion until Dorn's return.
VIIIth LegionThe Night Lords
IXth LegionThe Blood Angels remained relatively intact from the Horus Heresy. However investigations into some of the Battles, and Khornate Deserters required Sanguinius to reveal The Red Thirst to The Judges. Sanguinius was allowed to keep his legion intact, but IXth was forbidden from creating chapters. Sanguinius was required to report his legion to Fulgrim and the ordo biologius for regular investigations until a solution to the Red Thirst was found. The Moratorium on the chapter founding was lifted in M33 with the creation of Regula Celeste.
Xth LegionThe Iron Hands served with distinction and valor through most of the Heresy. The only concern came from Ferrus Manus himself, who expressed his concern about his Legion's growing ties to The Mechanicus.
XIIth LegionThe World Eaters were a curious case. While the accounts of the deserters of the Legion told horror stories of what Angron had done to them: from the butchers nails, to massacre on maccragge, to his fall to Nurgle. Many of The High Lords wanted to renew the Imperial Hounds chapter, but The World Eaters refused. To add further complications, some, such as Kharn insisted on keeping the butcher's nails as part of their tradition, seeing it as no different than The Glove of Rogal Dorn. Eventually concluded that all successor chapters of The World Eaters would not be permitted to use the butchers nails. The Imperial Hounds would be kept as "penitent" legion where those loyalists who refused to have the butcher's nails removed would serve.
XIIIth LegionThe Ultramarines was considered destroyed beyond repair, containing less than a fraction of its former forces. While some were concerned about their newfound religious devotion to their Primarch, and to The Realm of Ultramar the High Lords were pleased with Jaghatai's Codex Proposal and saw the Ultramarines as key to reuniting Ultramar with The Imperium. They were willing to allow the Sons of Gulliman to practice according to their own ways.
XIVth LegionThe Judges were impressed with the individual loyalty shown in the Death Guard by the sheer magnitude of Deserters. The fact that there were more Deserter Death Guard Astartes than there were Loyalist Dark Angels both Astounded the High Lords and became a point of humiliation to The Lion. The Death Guard were permitted to remain a Legion and form chapters with minimal restrictions. Nathaniel Garro offered the Position of "Honorary Primarch," and was made Commander of The XIV Legion, which was renamed The Sons of Garro.
XVth LegionGiven the complete and absolute destruction of The Thousand Sons during the Great Treachery, investigations into the Legion were about whether or not the Legion should be recreated. Magnus the Red was forced to disclose his deal with Tzeentch and the mutations of his legion. The Investigators determined that until the mutations in Magnus' Geneseed were resolved, the XV would be dissolved. Magnus would be permitted a small force of astartes that would be carefully observed for defects.
XVIth LegionWhile losing less than The Space Wolves, or even The Dark Angels, Horus Lupercal still had to account for the magnitude of traitors his legion possessed. Especially since such traitors and deserters hobbled the Imperium's effort to strike back against Lorgar and Alpharius. Horus revealed the incident of the Anatheme Blade as well as the Mournival's fall to chaos. Ultimately the High Lords and Valdor determined that the corruption had little to do with horus himself, since the blade corrupted what were otherwise perfectly normal emotions. It was Horus' account that ultimately swayed the High Lords and Constantine Valdor that the Council of Nikea not only needed to be revoked, but that every legion will need some sort of expertise in protecting against the forces of corruption. Following the council Horus requested permission to step down from his position of warmaster for the new role Legiarch who would among other things inspect the Emperor's legions from the infiltration of chaos. The high lords agreed, and the Sons of Horus reverted their name back to The Luna Wolves.
XVIIth LegionExpecting to find a legion thoroughly corrupted by Chaos, the Judges were surprised to discover just how much Lorgar was despised within his own legion. There were at least 4 chapters worth of the XVIII remaining, most of them a remainder from the old Imperial Heralds. The judges determined that all of those Word Bearers who were from Colchis were to form Penitent Chapters such as "The Sin Bearers," while those from Terra were allowed to form chapters and rebuild their legion under "The Imperial Heralds."
XVIIIth LegionThe Salamanders and their Father Vulkan had been left during the heresy to fend for themselves. Trapped between Drukhari raids and assaults from Luther's Imperium and The Black Legion alike. Despite this, The Salamanders endured, and the people of The Ultima Segmentum did not forget. The Council decided that the best course of action was to turn over most of the Segmentum to Vulkan's control. The Salamanders would server their father, the Segmentarch and defend the Imperial frontier from newfound threats. This decision suited Vulkan and His Legion just fine, as the events of the Treachery had made him more provincial, and disillusioned towards the greater Imperium.
XIXth LegionAs of the Council of Terra, Neither The Raven Guard nor their Primarch had been seen since the beginning of The Horus Heresy. They had vanished without a trace. While Konrad Curze spoke about visions of an All-consuming Dark Raven, His Brothers (Sanguinius, Vulkan, Russ, and Magnus) all spoke to his good character, and devotion, as they believed it was impossible that he would fall to chaos. The Judges decided to postpone a ruling on XIX until more information was discovered. As such the Legion was considered to be lost, but not retired, with permission to form chapters. It was not until the war of the Fallen Primarch that Corax's terrible fate was revealed.
XXth LegionDespite the not insignificant number of Alpha Legion Loyalists, after investigation and interviews, it was determined that Alpharius/Omegon's influence was impossible to truly remove, and the Legion was too dangerous to be allowed to exist. The XXth Legion was officially disbanded, and all records of their activities purged. Those who remained loyal were expected to submit to The Emperor's Mercy.
Decision: The Fate of The Imperial Truth and ReligionThe Council of Terra was an unquestionable victory for the Detractors of the Imperial truth, with even its defenders unwilling to sacrifice anymore of the Imperium for its well-meaning intentions. In its place was a revised Imperial Truth that was made to stand alongside the religions of man. The Matter of Religion was left open to the individual segmentarchs.
Council of Nikea and PsykersThe Council of Nikea was declared to be null and void. In its place was "The Canon Thaumaturgica."
The Canon Thaumaturgica was composed primarily by Magnus The Red (in Consultation with Khan, The Lion, and Horus).
The canon provided new guidelines for the regulations of Librarius in Space Marine Legions.
Additionally, it created an Imperial-wide Protocol for Psykers, their treatment, and their expectations.
The Black Ships were instituted in this, requiring a tithe of Psykers to be brought to Terra.
Magnus also provided his own consultation for the use of Psykers in The Codex Astartes, eventually adding his own section The Regula Prosperae and contributing some of his own rebuilding legion to some space marine chapters
ReligionDetermining that the continued existence of Religion was tabled until The Emperor was well, for the sake of both monitoring religion as well as gaining more support and stability The Primarchs set up avenues for limited practice of religion.
The different religions of the Imperium were permitted a single High Lord, the "Ministorum Fidelarum" who would address the concerns of those who practiced a belief.
In place of the Imperial Truth was The Terran Creed A set of 53 precepts that offered a religious test allowing some religions to survive while Worship of the Ruinous powers or The Emperor was thoroughly. The Precepts should not be considered a "bill of rights" or guarantee of privileges. They are better thought of as a smokescreen that permits the Imperium's governance to tolerate or persecute religion as it sees fit.
Lorgar's Imperial CultThe Imperial Cult, officially branded The Lorgarism Cult, was declared heretical to "New Imperial Truth." All those who followed it were given a year to register themselves, publicly renounce the teachings, profess the New Imperial Truth, and submit to inspection. Those who refused were hunted down and put to death. The Aurelian, Promethean, and even "Mechanicus Cult" took advantage of the situation, convincing many of the Imperial Cult to switch to their faith. Copies of The Lectitio Divinitatus and other symbols were burned.