Heresy & Rebirth

Heresy & Rebirth is an AU Lovehammer universe where the Senshi are not born into the 40K universe.

Heresy
In the 31st Millenium, Lorgar falls to Chaos as per Warhammer canon and via Erebus manages to corrupt Horus, who believes he is doing this for Serenity's sake.

He's to some extent part of a trinity of power at the centre of the Imperium: the Emperor, Serenity and Horus. For the first decades of the Great Crusade the three of them were alone, correspondingly important and quite possibly to some degree co-dependent. But at the end of the Crusade the Emperor has retired back to Terra and his secret pursuits, Serenity is probably increasingly involved in the Terran Council and administering the Imperium herself and Horus is Warmaster, no longer first among equals when it comes to his brother Primarchs but their clearly appointed leader.

At this point there is a period of reaching out with both Horus and other agents of Chaos attampting to win over the Primarchs and other prominent leaders within the Imperium. (At the same time, the Cabal are also trying to manipulate the situation by approaching Alpharius with a view to recruiting him). Given Horus' stated concern that Serenity may be in danger from the Emperor he's got every reason to reach out to Primarchs known to favour her.

At the same time, he knows that Magnus the Red is onto him and would certainly send the Space Wolves after him as in canon. That Serenity would neutralise Leman Russ is probably not something he would expect, but it also removes her from Terra, creating a window of opportunity to act while she is not there to be caught in any crossfire. Unfortunately it also shows a split between Horus and Serenity with the one encouraging Russ to kill Magnus and the other forcing him not to. At this point Horus has to act fast.

There are two logical groups of Primarchs for Horus to look to for support: his oldest comrades and the Primarchs who were his students. The first group would be Rogal Dorn, Magnus the Red, Leman Russ, Perturabo, Fulgrim, Ferrus Manus and Lorgar. The second group is Mortarian, Angron and Alpharius (Corax not being close to Horus), although Konrad Curze - having been Fulgrim's student and a close friend to both Mortarian and Horus can probably be included if the Emperor's Children and Death Guard turn.

Magnus and Lorgar have already made their respective loyalties plain and as the Space Wolves were designed to take down a rogue Legion, it's probable that Russ' loyalty is also not in doubt. Dorn is an old and trusted ally... but he's also responsible for protecting Terra so any approach to him risks alerting the Emperor. While Horus might think he could be won over, it would be an approach made once everything else is lined up. Fulgrim, being worked over by a Daemon Sword already, is a relatively easy convert and being best of friends with Ferrus Manus seems likely to turn him which succeeds - Ferrus Manus, always hard and ruthless, has been primed by Lorgar about sacrificing Serenity to remove a weakness in the Imperium.

Then there's Perturabo. Horus tells Perturabo that the clash at Prospero is a split between the Emperor and Serenity and that Horus is going to Terra to reason with their father. In the meantime, there's a suggestion that Roboute Guilleman might be being brought in to replace Serenity as heir. It's not a strong story but Horus is pretty good at this and this sets up Perturabo to block the Ultramarines from intervening.

Of the 'junior' Primarchs, Alpharius ostensibly falls in with Horus, albeit leaving 'Alpharius' with a rump who can plausibly play loyalist if things turn sour (basically straddling the fence). This leaves Mortarion, Curze and Angron. All have strong reasons to support Serenity over the Emperor and are persuaded to join Horus to 'save her'. However, they are probably at least a little wary and it's more a case of playing along while they try to find out what's going on - with the provisio that if Horus is right then they would side with him. In particular they covertly send a mission to Prospero to alert Serenity.

Chaos (via Lorgar) will push the pace. They know this can't hold up if Horus meets Serenity directly, so they push him to make a rapid push for Terra to confront the Emperor. They'll also do their utmost to prevent the mission to Prospero from arriving. Even a rapid flight for Terra will leave Horus' fleet in the Warp for an extended time and at this point Chaos pulls out all the stops to try to corrupt the wavering Primarchs and their Legions. Without Istavaan to crush three loyal Legions and purge Horus' ranks of loyalists, the numbers do not favour him: the Iron Warriors will wise up sooner or later and three of the 'Traitor Legions' are shaky at best. On the other hand, several of the Loyal Legions simply don't have time to arrive and fight.

Horus descends on Terra with eight Legions at his back. There are also large portions of the Imperial Army and the Dark Mechanicus moving to back him. He appeals to Rogal Dorn to open the Palace and surrender the Emperor, which is denied. Having already seized control of much of Terra, Horus orders the Palace to be taken, at which point most of the Legions fracture. While most of the Sons of Horus, Emperor's Children, Iron Hands and all of the Word Bearers and the complement of the Alpha Legion present obey, the bulk of the Death Guards, World Eaters and Night Lords have not been corrupted and nor have their Primarchs.

Still, Horus has most of the loyalists identified and the vast majority of his Imperial Army detachments and the Dark Mechanicus do not waver. By this point he has been substantially corrupted and is readily ordering the summoning of demons to add to his forces. Quite a number of loyalists in the Sons of Horus, Emperor's Children and Iron Hands are sacrificed to accomplish this. The bulk of the Death Guards, World Eaters and Night Lords try to link up with the Imperial Fists, bringing with them the relatively few loyalist Sons of Horus, Emperor's Children and Iron Hands they were able to rescue. However, Rogal Dorn refuses to admit them, leaving them trapped between the defenses of the Imperial Palace and Horus' army until the Emperor over-rules him. By the time they are admitted they have taken significant losses and the Night Lords have melted away to fight a guerilla campaign across Terra. The Death Guard form the rearguard and Mortarion himself falls covering the retreat.

The siege proceeds but without Perturabo on his side Horus makes even less progress than in canon. And while the Ultramarines and Iron Warriors, each believing the other legion to be traitors, are chopping each other up very satisfactorially, he knows that the Space Wolves and Thousand Sons will arrive on Terra before long, with the White Scars and Blood Angels not far behind. (The Dark Angels, Salamanders and Raven Guard are still a considerable distance away). When the first Space Wolf/Thousand Sons ships are sighted, he drops the shields on his flagship as an invitation for the Emperor to board.

The Emperor does of course, accompanied by the Custodes, Angron, Rogal Dorn and hundreds of Imperial Fists and World Eaters. Serenity, working with Magnus the Red, teleports an otherwise impossible distance with her own bodyguards to join in, leaving Magnus and Russ to work together against the bulk of the Traitor Legions. Ultimately Horus kills Angron, destroys Serenity's body and leaves the Emperor with almost mortal wounds before being cleansed by Serenity's parting shot, along with hundreds of corrupted Sons of Horus. Lorgar, Fulgrim and Ferrus Manus gather their troops and flee for the Eye of Terror. Alpharius (or possibly Omegon) is killed by Curze and the Alpha Legion scatter.

Rogal Dorn takes Horus into custody and manages to get the Emperor onto the Golden Throne in time to save his life before rallying his Imperial Fists to pursue the Traitor Legions. This leaves a composite War Council/Terran Council led by Magnus, Russ and Curze in charge until other Primarchs and adminstrators can arrive. It's this tribunal that sentences Horus to life, not death, although he is stripped of all Title, Rank and Office. The Sons of Horus, Word Bearers, Emperor's Children and Iron Hands are officially disbanded. Survivors of these Legions are divided into traitors (either fled or swiftly executed); repentant (mostly Sons of Horus cleansed by by Serenity) who are kept in close confinement; and loyalists, who are mostly attached to the other Legions as a temporary solution.

In addition to the devestation of Terra and Mars and the loss of traitor armies and legions, the Imperium also faces substantially depleted loyalist Legions. The Ultramarines and Iron Warriors have both taken very heavy losses facing each other. The Death Guard and World Eaters have taken similar casualties along with losing their Primarchs. The Night Lords are in a slightly better position and a large number of the Alpha Legion emerge (possibly with 'Alpharius' at their head claiming the other Alpharius was an imposter) and declare themselves to be a loyal faction of that Legion just as there are loyal survivors of the other Traitor Legions.

Almost worse than the losses (which though savage are far less than canon) are the divisions remaining between the Legions. The Night Lords, World Eaters and Death Guard are bitter at their 'betrayal' by the Imperial Fists, while the Iron Warriors and the Ultramarines are at each other's throats. The Space Wolves, without Serenity's presence, are on the brink of resuming their attack on the Thousand Sons (which might be the [I]only[/I] thing that the Dark Angels agree with them on). Added to this is Roboute Guilleman's proposal to break up the Legions. Ultimately it takes all the influence of Sanguinius, Jaghatai Khan and Vulkan to hold any sort of consensus and their Legions, being the most intact, are largely holding the Imperium together.

Rebirth
In the 41st Millenium, Leman Russ and Corax arrive on Fenris with thirteen young humans in stasis. These are the reincarations of thireen of their brother Primarchs.

Of the original Primarchs, Perturabo is also confirmed as alive and governing the Imperium from Terra while Roboute Guilleman is alive but in stasis on Macragge to prevent mortal wounds from killing him. The Ultramarines are in a state of semi-rebellion against Perturabo's authority.

The reborn primarchs include Matthias (Magnus the Red), Dorias (Rogal Dorn), Teleute (Horus), Prima (Alpharius) and Umi (Angron).