Editing Alternate Heresy (section)

==Deviations==
'''Deviations''' are generally similar to the original canon but with some changes. In the vein of "What If...?" [[Marvel Comics]]. A majority replace the arch-traitor with another primarch. It is something close to an obligation to have Khorne fail to take the Blood Angels.

===The Dornian Heresy===
The '''[http://web.archive.org/web/20211213141252/https://bolterandchainsword.com/heresy/thedornianheresy.pdf Dornian Heresy]''' was the 40K web forum Bolter & Chainsword's first major project to switch the allegiances of the various Primarchs during the Heresy, and explore what would have happened to the Legions under their command if they had fallen or not.

Unlike the following scenarios, which were largely either FF.net/AO3 stories or thought exercises in random threads on /tg/, this was a full project, with accompanying [[Index Astartes]] articles, a wiki and quite a bit of fluff, most of which can still be found quite easily.

Essentially, during the incident on Davin, [[Magnus the Red]] arrives on time to exorcise [[Horus]]' infection instead of relying on [[Erebus]]' rituals. While successful at both saving the Warmaster's life and preventing him from becoming corrupted, it did leave him out of commission. Following their temper tantrum, the Chaos Gods decided that the next best choice was [[Rogal Dorn]], who had been going on overdrive with his pet pain glove.

In the end, we get the following betrayals: The [[Space Wolves]] fell to [[Khorne]] as part of their rabid psyker-hate. The [[Blood Angels]] fell to [[Nurgle]] in an event almost identical to the canon Death Guard, plus the bit where they practically owed their lives to Nurgle and were now forced to recruit mutants due to how fucked-up their gene-seed is. The [[White Scars]] fell to [[Slaanesh]] because Khan got drunk off his vanity and ego while sending his loyal sons to die on Chogoris. The [[Raven Guard]] fell to [[Tzeentch]], Corax himself being fed haunting visions of the future by Big Bird himself. The [[Salamanders (Chapter)|Salamanders]] fell to [[Malal]] out of total disillusionment with the Imperium, and [[Rogal Dorn]] himself became the arch-traitor, with his [[Imperial Fists]] supporting [[Chaos Undivided]] (renaming themselves the [[Black Legion]] after the failure of the Heresy). The [[Ultramarines]] did not fall to [[Chaos]], but instead became [[Reasonable Marines]]; they seceded from the [[Imperium]] alongside much of the Ultima Segmentum, and now exemplify progress while fighting off the [[Tau]]. The [[Iron Hands]] seem to have gotten mixed up with the [[Necrons]], while the [[Fallen Angels]] won out over the loyalist [[Dark Angels]], with Luther triumphant.

On the Imperial side, the [[Word Bearers]] became the [[Ecclesiarchy]] (with no [[Kor Phaeron]] to twist it all to heresy - he proved incompatible with the gene-implants), the [[Iron Warriors]] remained siege masters, the [[Sons of Horus]] became the crusading [[Black Templars]] (after almost disowning Horus' foolishness which led to his martyrdom in a manner almost identical to their canonical rebranding), the [[Emperor's Children]] remained exemplary perfectionists (except for [[Fabius Bile]], but he's dead now... except not), the [[Thousand Sons]] became blind psychic warriors (see: [[Grey Knights]]), the [[Death Guard]] became the core of the [[Inquisition]], the [[World Eaters]] became serious instead of angry, the [[Night Lords]] remained loyal [[Scary Marines]] without going over the edge, and the [[Alpha Legion]] were just as sneaky and just as anti-[[Ultramarine]], but still loyal (apparently [[The Cabal]] wasn't that convincing in the Dornian Heresy).

How the Space Marines are organized is also flipped, as the legions falling to Chaos occurred because of them being separated by all sorts of circumstances, so Abaddon (who takes over as leader of the Imperium after the Emperor's battle with Dorn) organized the legions into a few giant armies (by Space Marine standards).

It's pretty [[awesome]]...except that, as most alternate heresies are wont to, it all amounts to some absurd amounts of marine-wank (almost as if the whole Heresy is about them, huh). Perhaps the most particular is the Reign of Blood, where the [[Sisters of Battle]] never existed, because they were wiped out by the [[Word Bearers]] when they were still the Brides of the [[Emperor]], and [[Goge Vandire]] (who was now the new Chapter Master following Lorgar becoming a martyr post-heresy) wasn't overthrown by some simple preacher, but by a novice marine named [[Sebastian Thor]]. To be fair, can you really imagine the Word Bearers not recruiting him? Meanwhile, all of the xenos factions are left to mere footnotes or mentions (just as [[Games Workshop]] intended) and the impact this has had on the Imperium at large is left to interpretation.

===The Imperial Heresy===
{{Main|The Imperial Heresy}}
In the '''[http://suptg.thisisnotatrueending.com/archive/16830576/ Imperial Heresy]''', the [[God-Emperor of Mankind]] decided "if you can't beat 'em, join 'em" and sided with the [[Gods of Chaos]].

===The Eldar Gambit===
In the '''[http://suptg.thisisnotatrueending.com/archive/14094031/ Eldar Gambit]''', [[Eldrad]] meets the Emprah the day before the final assault on the Vengeful Spirit, offering assistance in exchange for closer [[Eldar]] - [[Human]] cooperation later.

The basis of the pact is that instead of taking the mortal blow that Horus throws at him on accident, he does it deliberately, and uses the energy of his own death to attack the Chaos Gods directly, specifically Slaanesh. He steals the stomach of Slaanesh and incorporates it into himself, so now all Eldar souls will go directly to him when they die, keeping them safe from the depredations of Chaos.

The thread was mostly speculation on how a united Imperium of Man and Eldar Empire would work together... and it's actually pretty awesome. Ollanius Pius being revered by guardsmen as an Avatar of Khaine(or Khaine revered as his avatar) [[Awesome| and killing Horus right after Horus defeated the Emperor]] (<s>albeit he was weakened from fighting the Emperor</s> he's a motherfucking Primarch jointly possessed by all Four of the Chaos Gods, there is no "albeit" about it), Space Marines with soulstones to keep the forces of Chaos away from loyal marines, a fractured Adeptus Mechanicus (with four factions - Traitor, Loyal, Machine God fanatics and Fundamentalist (doesn't use Eldar tech that is now more freely available)), and more.

===The Roboutian Heresy===
The true heresy has begun: Papa Smurf takes the place of Horus and fucks over the Imperium. Much shedding of blood, sweat and tears ensues, with generous helpings of manliness on the side. It's pretty [[awesome]].

Inspired by the above mentioned Dornian Heresy, circumstances happen that lead to the Primarchs who turned traitor in canon to stay loyal and the loyalists to turn traitor. For this Heresy's loyalists this ranges from having a small point that causes a major divergent in their lives, like Konrad and Angron, to having completely different lives like Lorgar. The Traitors all at a certain point have a moment that led them towards Chaos, some better done than others, even the fic's writer admits El'Jonhson's could have been done better, but the rest bring much tragedy and sorrow, though a bit less so with Vulkan (his moment of divergence ''is'' absolutely horrifying, but it isn't as sad because of how awful Vulkan and the Salamanders are in this timeline). However, even Vulkan and the Salamander's horrors pale in comparison to that of Corvus Corax and the Raven Guard.

Of the traitors, Vulkan was raised- then killed by, a female [[Dragon|fire drake]], causing him to realize his immortality early on and gain a god-complex. This wish came true when he, hating the 4 chaos gods but believing SO HARD in his own superiority, actually [[Awesome|turned himself into the chaos god of greed and pride!]] I.e., a giant chaos version of [[The Hobbit|Smaug]]. Rogal Dorn fell to [[Khorne]] due to a massive ork fleet almost destroying the Inquit System and destroying the Phalanx, leading to him never using his [[TTS|magic pain glove]] to temper his anger. Lion El'Jonson spent too long in the warp-tainted wilds of Caliban and became corrupted by [[Tzeentch]]. Sanguinius grew up with an even greater fear of mutants and deviation, causing enough doubts and fear that, when [[Slaanesh]] came knocking, he gave himself and his legion up willingly. They then turned into full-on horny space-[[vampire]]s who get off on drinking blood. For being the archtraitor, Rowboat himself had a pretty lazy bog-standard "hometown and parents were destroyed and became more brutal because of it" backstory as well as being manipulated by Be'lakor, [[Archaon|meaning he's a once great hero who turned evil through a combination of losing loved ones and Be'lakor playing him like a fiddle]]. Jaghatai grew up with chaos worshippers and Russ lost his pet wolves, Geri and Freki, while executing the [[Lost legions]]. Ferrus became an utter social darwinist and got infected by [[Nurgle]] when he tried to blow up a daemon world. Then there's Corvus Corax, who was in the care of the mad scientists of Kiavahr and, seeing his immense scientific potential, proceeded to [[Grimdark|slice him up, poison him, disembowl him, tear off and reattach his limbs, and countless other horrific tortures]] in the name of 'science.' It only gets worse, as he himself became a mad scientist, created horrific astartes clones called ''Spawn Marines,'' and became an avatar of a previously unknown chaos god of emptiness and the void (Malal? Worse. Much, much worse.)

For the loyalists, Konrad had a loving mother who helped develop his moral compass into less of a Punisher and more like Batman. When Horus first met his father, their meeting was more cordial and he saw that Big E was just a tired, old man who wanted the best for humanity, under all the glitz and glamour. Magnus fought a titanic psychneuein on Prospero, learning to use his muscles instead of his powers when the creature was immune. When Tzeentch offered to save his sons from the Flesh Change, Magnus said no and basically cured it himself. Now much more cautious, he sent [[Ahriman]] to help Horus during the crusade, allowing them to heal Horus and thus the Warmaster never fell. Peturabo, as new Preatorian of Terra, performed a far better job than Dorn did in the Horus Heresy, making a stellar defense for Terra and even [[Reasonable Marines|constructing huge rings of planetary fortresses around the Eye of Terror and Ruinstorm to keep chaos caged up]] after the Heresy, called the Iron Cages. By killing his Witchlord foster father, Mortarion learned how to [[get shit done]] as he took up the role as Big E's executioner, killing/banishing both Jaghatai and Vulkan singlehandedly before his demise in two separate moments of [[Awesome]]. Lorgar and Angron had loving parents and used their psychic charisma to lead revolts against their cruel planetary governments, with Angron never getting the Butcher's Nails, and Lorgar slaying [[Kor Phaeron]] when he saw the horrors the cults of chaos were capable of. Fulgrim having a few librarians with him meant he never took up the daemon sword of Slaanesh... buuuut the [[Eldar]] didn't know that, so [[Eldrad]] convinced the Dark Eldar to kidnap him and subjected him to [[grimdark|decades of disgustingly extreme torture]] so Slaanesh couldn't have him, on the pretense of a faulty prophecy. '''Thanks Eldrad!''' Finally, Alpharius Omegon had their pragmatic and ruthless ways tempered by Konrad, so they turned out to be one of the single most valuable chapters of astartes the Imperium has. The Alpha Legion also became buddies with the [[Rogue Traders]], which is pretty cool.

Notably, Fabius Bile is still evil, but a little less so here given that here he has a reason for being evil that his main version lacks, and even he is ''horrified'' by the sheer awfulness of the corrupted Raven Guard. On the Flip side, Aeonid Thiel is still on the side of good and was still kicking Traitor Marine ass in the Heresy. Just that said Traitor Marines were also wearing his own colors. Thanks to his theoriticals and stratgems he has made against his foes, alongside being an incredibly crafty fella, he has amassed a bunch of fanboys from the ''Loyalist Alpha Legion''. Not bad.

* [https://forums.spacebattles.com/threads/the-roboutian-heresy-a-warhammer-40k-alternate-universe.440554/ Can be read here (also contains sidestories and word of god)].

* [https://forums.spacebattles.com/threads/if-the-emperor-watched-tts-extras-thread.508247/page-2#post-33704905 Can also be read here] (see threadmarks) for reactions from the primarchs and the Emperor himself.

===The Leonine Heresy===

What it says on the label: '''[https://www.fanfiction.net/s/14001243/1/ The-Leonine-Heresy]'''

The First is taking his turn at ruining the galaxy. This is one of the more unique Alternate Heresies in that the primarchs are not swapped 1 for 1, but it is a mix of loyalists and traitors on each side. Mix that with an emphasis on grimdarkness and enough slaughter to impress even [[Khorne]], and you get a story as colossal as the Imperial Palace. Inspired by the Roboutian Heresy and the Shape of the Nightmare to Come/Age of Dusk fanfics.

Like with the Roboutian Heresy, differing circumstances have resulted in drastic personality changes for the various primarchs. For the loyalists, Konrad Curze and Lorgar both got a stern talking to from the Emperor, causing them to remain loyal. Their roster includes Leman Russ (aka Odin), Konrad Curze (blind-folded avatar of justice who sacrifices himself fighting the Archtraitor), Ferrus Manus (WHO COULD FORGET HIM?), Mortarion (pissed beyond belief that he has to be a loyalist), Horus Lupercal (doesn't do too well in the Iron Cages), Lorgar Aurelian (the Saint who arrives too late to save the day), Vulkan (Praetorian of Terra), Corvus Corax (first victim of the Heresy who gets his head pulped like Oberyn Martell), and Alpharius and Omegon (who realized a group of xenos probably aren't the most trustworthy).

For the traitors, we have Lion El'Jonson (Archtraitor as a result of the Rangda and a puppetmaster worthy of [[Tzeentch]]) , Fulgrim (Landed on Chogoris, depressed beyond belief because he's the chosen of Nurgle with a Blight-crippled legion), Perturabo (Allied with Vashtorr, Master of the Eye of Terror, and Breaker of Fists and Luna Wolves alike), Jaghatai Khan (lands on Chemos, gets teamkilled by Guilliman), Rogal Dorn (hates Perturabo, hates the Emperor for not making him Praetorian, simple as), Sanguinius (the Red Angel, Chosen of Khorne for once, has the Sanguinor for a stand), Angron (kills Corax, only to be team-killed by a berserk Sanguinius shortly after, his sons have renounced him to serve Malal/Unicron/something), Roboute Guilliman (Chosen of Slaanesh, everything he says is a reference, most often toward David Bowie), and Magnus the Red (Still Tzeentch, but utterly insane; his sons are now wild mutants instead of dusty robots).

[https://www.fanfiction.net/s/14001243/1/ Can be read here].

[https://forums.spacebattles.com/threads/the-leonine-heresy-a-warhammer-40k-alternate-universe.1003694/ Can also be read here, but with more comments and responses from the author].

===[[Story:Warhammer High|Warhammer High]]===
Technically an Alternate Heresy, as in there was no Heresy at all and the Emperor decided Malcador's ideas were not stupid after all and made 19 female Primarch children to give the Primarchs some responsibility Post-Great Crusade, something to live for, a chance for family, and because he really wanted Grandkids.

It's a bit.....[[Slaanesh|weird]].

===Imperium Ascendant===
The Most Fuck-Ass Awesome Timeline: The Legion of the Damned are sent back in time by the Throne-Emperor to stop the scattering of the Primarchs by Argel Tal. After they succeed, the Emperor of the past looks upon the future that is the galaxy of 40K and vows to ensure that such a nightmare will not come to pass as the Ascendant Imperium strikes out against the darkness. In short, The Emperor learns where the Canon timeline will lead, and decides to take corrective measures. This leads two major downsides compared to the main timeline in that Ultramar becomes a Chaos empire instead as Guilliman (Marco Augustio) never landed there to unite the 500 worlds, and Malal is actively out and about feuding the with the 11th Primarch. There is also excellent writing about Gene-seed organs both vanilla and Primaris, plus a few neat extra organs that the original Emperor dismissed as too little utility for available time including a legion specific organ for each legion (akin to the Canis Helix for the Space Wolves, and the Grey Knights get the coolest named one called the Ghost Heart).

The original author threw a hissy fit after TTS announced it would no longer continue and handed the project over to another writer. First part [https://forums.spacebattles.com/threads/imperium-ascendant-heresy-less-40k.596194/ here], and the second [https://forums.spacebattles.com/threads/imperium-ascendant-redux-a-continuation-of-a-heresy-less-40k.968339/ here].

The original author got depressed by the chaotic corruption of GW and didn't feel like continuing and handed the project over to another writer. First part [https://forums.spacebattles.com/threads/imperium-ascendant-heresy-less-40k.596194/ here], and the second [https://forums.spacebattles.com/threads/imperium-ascendant-redux-a-continuation-of-a-heresy-less-40k.968339/ here].

===[[Nobledark Imperium]]===
{{Main|Nobledark Imperium}}
 
Probably one of the more divergent Alternate Heresies out there. Like [[Warhammer High]] technically an Alternate Heresy despite there not being a heresy at all. Nobledark is as much a retelling of the 40k universe with intentional twists as it is a straight alternate timeline, sort of like [[Hektor Heresy]] or [[Imperium Asunder]], though in general all parties receive a buff to reason and common sense, as you would expect from a universe that is [[Noblebright|nobledark]] as opposed to [[grimdark]].
 
Instead of earning the ever-lasting hatred of the Chaos gods by doing {{[[Alpha Legion|REDACTED]]}} that led to the creation of the [[primarch]]s (who in this timeline are the Emperor's greatest, though otherwise similar to canon in name and deed), in this timeline the [[Emperor]] plotted with [[Eldrad]] and agreed to <s>[[Lord of the Rings|a last alliance of elves and men]]</s> a team-up between the nascent [[Imperium]] and the [[Craftworld Eldar|Eldar]] to free [[Isha]] from [[Nurgle]]’s garden to weaken the [[Chaos Gods]] in exchange for access to the [[Webway]] and anti-Chaos lore.
 
The Imperium and Eldar expect to go their separate ways after the Raid on Nurgle's Mansion, until Chaos decides to supercharge the [[War of the Beast]] in order to show those mortals what happens when you steal fire from the gods. The Chaos Gods don't manage to turn any primarch (though they get really close with Horus), the Emperor having told the primarchs what Chaos what it is and why it is important to ''not touch it'' beforehand. Humanity and Eldar are forced into an alliance once again, resulting in an Aesir-Vanir-esque political marriage between the Emperor and Isha. Although things are bad with the biggest green tide the Imperium has ever seen and [[Luther]] convincing the majority of [[Dark Angels]] to go traitor, they only gets worse when the true mortal catspaws are revealed.
 
Because that buff to competence and common sense? [[Chaos]] gets it too. And in a spectacular display of long-term planning, instead of consuming ALL of the pleasure cult-worshipping eldar in the Eye upon their birth, [[Slaanesh]] only consumed MOST of them. So now in addition to daemons, orks, and traitors, you have an entire army of insane, Chaos-worshipping fair folk who just declared holy war on the [[Imperium]] and their [[heresy|heretic]] [[Eldar|kin]].

And it all kind of spirals out from there.
 
Can also be found at [[Nobledark Imperium Drafts]], the other main page for the project.

===Shattered Imperium===
{{Main|Shattered Imperium}}

The canon legions fracture into more than two factions. Imperial Fists, Raven Guard, Salamanders, and Blood Angels remain loyal to Emps. Sons of Horus, Word Bearers, Alpha Legion, and White Scars go Chaos. Thousand Sons, Iron Hands, and Emperor's Children go [[transhumanist]]. Death Guard, World Eaters, Night Lords, and Iron Warriors go egalitarian. And finally the Ultramarines, Dark Angels, and Space Wolves go independent of everyone.

===MidHammer===
{{Main|MidHammer 40,000}}

The setting that tries to find a balance between the grim darkness of the original Warhammer and [[Setting:Brighthammer 40,000|BrightHammer]].

===The Vulkanite Heresy===
A less-grim, less-dark, but still solidly grimdark timeline. Vulkan can't stomach the purges of the Lost Primarchs and goes renegade. Eventually this makes him easy prey for Lorgar and Tzeentch, and Chaos gets a Heresy War. Featuring a mix of canon loyalists and traitors in the heretic faction, more renegades and semi-traitors (Oh, Hi Malal), and a decompressed timeline of events. Indexes Astartes are viewable on [https://archiveofourown.org/works/20434316/chapters/48479066 Ao3] and [https://www.reddit.com/r/VulkaniteHeresy/ reddit], with some older material about the primarchs also on reddit. That will eventually be superseded by ''Biographica Primagenesis'' entries for them, and some Xenos entries, particularly for changes wreaked on the Eldar, will be inbound, but that will all be after the Index Astartes are finished.

===The Sanguinary Schism===
A fan heresy with Sanguinus as the traitor warmaster. No wiki yet cause the admin is tech illiterate https://www.facebook.com/SanguinarySchism/

There is also another version of the Sanguinary Heresy, [https://www.fanfiction.net/s/12957151/9/The-Sanguinary-Heresy here]

===If the Emperor Watched [[If the Emperor had a Text-to-Speech Device]]===
Due to mysterious warp nonsense, the canon timeline just after the triumph of Ullanor when all the Primarchs minus Alpharius Omegon (who arrive later) were together receives the TTS videos and other Lexicanum, 40k Wiki, Codex and 1d4chan information in the form of videos and text files. The Emperor and the Primarchs (minus the twins who as stated arrive later and the lost two who were already purged) watch them to great hilarity. The main thread is on Spacebattles [https://forums.spacebattles.com/threads/if-the-emperor-watched-the-text-to-speech-device.408752/ in this thread], while side stories and reactions to fanfiction, homebrews and other files like the wiki articles and the alternate heresies are on [https://forums.spacebattles.com/threads/if-the-emperor-watched-tts-extras-thread.508247/ this thread]. The Extras thread got locked by mods and the main thread is locked due to hiatus so things have moved to SufficientVelocity in [https://forums.sufficientvelocity.com/threads/the-emperor-and-primarch-react-to-tts-and-pretty-much-everything-ever.89548/ this thread]. The previous thread has been abandoned. A continuation has been made [https://forums.sufficientvelocity.com/threads/emps-and-sons-react.97455/ here].

Main story is written by Praetor98 and sidestories of the main thread and all of the extras thread is made by readers.

====[[Messages for Dad]]====
Possibly one of the most popular fanfictions among the fandom, but many are unaware that it is actually a spin off of If the Emperor Watched If the Emperor had a Text-to-Speech Device, confirmed by Corvus Corax during chapter two of the AO3 Version and by Roboute Guilliman an extra chapter of the [[Spacebattles|SpaceBattles version]]. He himself started as an extra thread in SpaceBattles for users DuskDawnAndFate and Showtime178.

We follow the imperial family reacting to their future offspring

You can read on SpaceBattles version: [https://forums.spacebattles.com/threads/messages-for-dad-thread-warhammer-40k.623812/ Link Here]

You can read on AO3 version:[https://archiveofourown.org/works/21518860/chapters/51293176 Link Here]

===The Cyclopean Heresy===
What if Magnus the Red was the Arch-Traitor? The arrangement of Loyalist and Traitor Primarchs are completely different, with Mortarion of the Death Guard becoming Warmaster of the Imperium during the Heresy, replacing Horus who was stripped of that title when he went traitor.

Can be read [https://www.fanfiction.net/s/12600333/1/The-Cyclopean-Heresy here].

===Everqueen===
[[Isha]] manages to avoid being captured by Nurgle and being devoured by Slaanesh, and ends up incarnating to Terra during the Unification Wars. Big E finds her and decides to imprison her and make her his servant as she would very useful to his plans. Author has stated that no, the two will not have a romance between them.

Part one can be read [https://forums.spacebattles.com/threads/everqueen-warhammer-40-000.881555/ here], and part two [https://forums.spacebattles.com/threads/everqueen-reclamation-warhammer-30-000.1131742/ here].

===Renegades===
Shortly before the Canon heresy would have begun, the Emperor decides that he wants to be a god. He allies with the Chaos Gods and ropes in several Primarchs into his plan to make the Imperium worship him as a god. This does not go down well with Horus and Magnus, who start seeing dark changes in the Imperium and the way it is run. They create a coalition of legions to oppose the Imperial legions, and the civil war begins.

Renegades deals with the buildup to the civil war, and the civil war itself. It continues to this day. A good read, and a rather interesting one.

Can be read on AO3 [https://archiveofourown.org/series/3231139 here].

===The Fulgrimian Heresy===
An alternate heresy where it is Fulgrim who is the Arch-Traitor. Arrangement of Loyalist and Traitor Primarchs are different, with more primarchs remaining loyal to the Emperor than joining Fulgrim and the Traitors. It's an excellent read.

Can be read [https://www.fanfiction.net/s/12178465/1/Death-of-Unity-The-Fulgrimian-Heresy Link here]

===Alternate Heresy Community Project===
This is an alternate heresy with an interesting premise. Instead of the [[Primarchs]] landing where they normally do, they land on different planets, which causes them and their legions to have different personalities and areas of specialization. This causes a different heresy. The thread can be found [https://bolterandchainsword.com/topic/282390-alternate-heresy-community-project/ here]

===The Alpharian Heresy===
Another alternate heresy, where the planets the [[Primarchs]] land on are switched up. Alpharian of the Primus Legion falls to Chaos and causes a heresy that splits the Imperium. It consists of three reddit posts linking to documents. 
* [https://www.reddit.com/r/40kLore/comments/9x9hdx/f_nanowrimo_the_alpharian_heresy_the_primarchs/ The Alpharian Heresy, the Primarchs]
* [https://www.reddit.com/r/40kLore/comments/ai8jid/f_the_alpharian_heresy_corruption_of_the_primarchs/ The Alpharian Heresy, Corruption of the Primarchs]
* [https://www.reddit.com/r/40kLore/comments/aqh888/f_the_alpharian_heresy_first_phase_of_the_war/ First Phase of the War]

===Blood Tears of the Warmaster===
What if a paranoid Cabal killed Horus Lupercal on Ullanor before he could become Warmaster? How would the galaxy change?

Heavily diverges from the average "alternate heresy" type storyline. Really starts to show midway through the plot. Possibly one of the best written alternate heresies out there.

Can be found on Fanfiction.net [https://www.fanfiction.net/s/14324880/1/Blood-Tears-of-the-Warmaster-An-Alternate-Warhammer-40k-Heresy here]

'''SPOILERS:'''
* Sanguinius becomes upset over the death of Horus and falls to Chaos to get him back. He eventually becomes the focal point for the creation of the 5th Chaos God, of Sorrow. Terra falls into the Warp, Imperium Secundus is created, and teh Emperor fuses with Cegorach to become the God of Hope

===The Lorgar Heresy===
Following the Great Treachery of Lorgar, the Imperium of Man was left in ruins. The centuries of strife, revolts, and internicene fighting had undone nearly all of the work the emperor had done during the Great Crusade. Hoping to salvage what remained of a crumbling state The Emperor's Remaining loyal sons reorganized the Empire into a Feudal Kingdom.

Now In the 41st Millenium, the Imperium is finally winning its long and brutal war against chaos, but new threats are gathering. The Eldar and the T'au are rapidly expanding, the ancient alliance between Earth and Mars is rapidly fraying, and devouring swarm has appeared from the deepest cosmos.

You can read the stories of this Heresy on AO3: [https://archiveofourown.org/series/1846669 Link Here]

===The Corvidian Heresy===

Less of an “Alternate Heresy” but more of a “what happens if the Heresy was defeated much more easily?”

Series published on reddit in five parts:

Part one: [https://www.reddit.com/r/40kLore/comments/8bpw2l/the_corvidian_heresy/ The Corvidian Heresy: Summary.]

Part two: [https://www.reddit.com/r/40kLore/comments/8bzdmj/f_the_corvidian_heresy_part_ii_fate_of_the/ The Corvidian Heresy: Legions I-VII]

Part three: [https://www.reddit.com/r/40kLore/comments/8c7uhq/f%20the%20corvidian%20heresy%20part%20iii%20fate%20of%20the/ The Corvidian Heresy: Legions VIII-XIV]

Part four: [https://www.reddit.com/r/40kLore/comments/8cey1m/the%20corvidian%20heresy%20part%20iiia%20fate%20of%20the/ The Corvidian Heresy: Legions XV-XVII]

Part five: [https://www.reddit.com/r/40kLore/comments/8cncqc/f_the_corvidian_heresy_part_iiib_fate_of_the/ The Corvidian Heresy: Legions XVIII-XX]

===An angel's fall [40k Alt-heresy]===

Just another heresy of Sanguinius.

Horus disappeared into the warp on the way to Interex, Dorn and Perturabo united in the traitor team, and For some reason there are [[Skaven|Skaven fighting alongside the traitors]]

[https://forums.spacebattles.com/threads/an-angels-fall-40k-alt-heresy.1117348/all/reader/ You can read in SpaceBattles Here]

===Warhammer 40K: Legiones Astartes===
[[Armageddon|On the eve of Mankind's greatest victory, with near total domination of the stars,]] the greatest of the Imperium's commanders and most favoured son of the Emperor - [[Horus|Horus Lupercal - Primarch of the Sons of Horus and Warmaster of the Imperium's vast armies]], turned against the light of the Emperor. Convinced by [[ Chaos Gods|the dark whispers of the Chaos Gods]], he led a galaxy-wide [[Horus Heresy|rebellion against the Imperium, splitting the domain of mankind in twain.]] For nine brutal years, the loyal servants of the Emperor fought against their traitorous brothers in a war of almost apocalyptic nature.

Eventually, the Traitor Legions managed to make their way to the capital of the Imperium, to the Throneworld itself - Terra - birthplace of Humanity. In the ensuing battle, countless billions gave their lives in defence of the Emperor of Mankind. The servants of the Dark Gods ravaged and burned the planet, leaving it a husk of its former self. In the aftermath of this apocalyptic battle, Horus lay dead, his very soul destroyed by the psychic might of the Emperor, and the traitors' forces were broken and fled. Losses on the Loyalist side were just as grievous, the Primarch of the Blood Angels, Sanguinius, lay dead, and worst of all, [[The God-Emperor of Mankind|the Emperor Himself had been mortally wounded by Horus in the final moments of the battle]], forcing him to be interred in the Golden Throne.

[[High Lords of Terra|To rule in the Emperor's stead, the leaders of the major branches of the Imperium were brought together in a great council, from which they would forevermore dictate the rulership over the Imperium.]] Their first act was one of monumental importance, and consequence. The Great Crusade was to be renewed whilst the Imperium rebuilt, as the enemies of Mankind could be given no time to rest. The Horus Heresy had kept Mankind from its manifest destiny long enough, and they would not stand idly by. Whilst the this new 'Second Great Crusade' began, an important factor, once a common sight on the battlefield, was missing. [[Space Marines|The Legiones Astartes]] had been nearly shattered by the Heresy - [[Heresy|half their number had turned traitor]] - whilst the loyalists took massive casualties.

[[Rogal Dorn|The Praetorian of Terra, Rogal Dorn]], proposed that the Imperium should not only seek to rebuild the Legiones Astartes numbers, but to eventually expand them even further, [[Space Marine Chapter|by creating new Legions]]. To help guide these future Legions, they would fall back on the wise tenets of the Principia Belicosa, with additional wisdom added to it by Dorn himself. With the death of the strategically brilliant strategist and organiser [[Roboute Guilliman]] at the hands of [[Alpha Legion|Alpha Legion assassins]], Guilliman's proposed treatise, the [[Codex Astartes|Codex Astartes was never completed]], and therefore, never adopted. Thus, the dissolution of the Space Marine Legions into separate Chapters never occurred. Soon, the old Legions were rebuilt and returned to the field of battle, joined by brothers of a new generation, seeking to prove themselves in a new war against the Emperor's enemies.

Unfortunately, without the Emperor's guidance and leadership for the last ten millennia, the Second Great Crusade has suffered immensely. The High Lords and their appointed commanders remain unable to counter the threats that lurk in the darkest corners of the galaxy. Billions are slaughtered every day - victims of poorly planned assaults and ill-prepared defences on planetary scales. In this time of everlasting war, there is only one stalwart force keeping the flame of humanity burning - the Legiones Astartes.

More information in the [https://wh40khomebrew.fandom.com/wiki/Warhammer_40,000:_Legiones_Astartes WH40K homebrew] wiki and in the [https://wh40kfanon.fandom.com/wiki/Warhammer_40,000:_Legiones_Astartes WH40K Fanon] wiki


'''IMPORTANT NOTE: Do not confuse this AU with [[#Successor Legions|Successor Legions.]]'''


===Bellum Frigidum: Wtha if The Imperium Never Existed?===
One of the many Alternate Heresies being hashed out on the ImaginaryWarhammer subreddit. [[Unification Wars|Premise is, the Emperor loses the Unification War and is killed]], but not before the Primarchs are spread throughout the galaxy. No Astartes, the Primarchs never figure out how to reverse-engineer themselves. No Imperium, [[Human|instead multiple mutually opposing human factions.]]

[[Age of Strife|A world where humanity remains as divided as it was during the Age of Strife]]. A world where the [[Xenos|Xenos who were once mere footnotes now play a critical role in history.]] A world where only a few Primarchs are known to each other, and their friendships and alliances are as strange as those of those who live within their empires. A world where chaos is on its last legs and [[Chaos Cults|entire civilisations exist only to serve the Dark Gods]]. A world where the greatest galactic conflict is the impending war between [[Ultramar]] and [[Adeptus Mechanicus|the Mechanicum]] over who will decide the fate of humanity.

If you want to read more or contribute to the further development of this universe, [https://docs.google.com/document/d/10BfYqS5ZwUXETwFO_W3faoWt74JZ4mPfJ7B5c6LFOKw/edit?tab=t.0 check out the Google Docs].

===The Cipher Heresy===
The Cipher Heresy is an alternate Heresy where Leman Russ is the Arch Traitor. Yeah. That's... that's about it.

[https://archiveofourown.org/works/51137758/chapters/129205675 You can Read in AO3 Here]

===Heresy of Grey===
An alternate heresy featuring more ambiguous motivations, more divided loyalties, Primarchs revealing themselves individually for different reasons, people making bad decisions for sensible reasons, and a very different resulting equilibrium between the Imperium and Chaos.

[https://archiveofourown.org/series/2096220 You can read in AO3 here]

===Warped Origins===
The main focus of this AU is this: “What would the Legions and Primarchs be like if they lived different lives on their homeworlds?” Many Primarchs have their personalities and even their names changed—Alpharius is Warmaster and Emperor's favorite much to "second son" Horus's envy, Corvus *Tyrannus* is raised by Kiavahr's tech-guilds and becomes an unrepentantly cruel slaver and tyrant, Perturabo gets to be happy (at least until the Heresy), and so on. This results in the eventual Heresy playing out quite differently. Horus is still the Arch-Traitor, but his rebellion starts out as one motivated by politics and ideology, and it is the mysterious outsider Gawain Morogan (canon Lion El'Jonson...it's a long story) who corrupts the Traitor side to Chaos.

The two Lost Legions get filled in and explained in this AU as well, playing a small role in the plot.

[https://docs.google.com/document/d/1PqgWQ0UAhVcSts8dIN36vf7mieMgl-C2XNZ9z6o0JRo/edit?tab=t.0#heading=h.evz8xhmj4i5x See the Google document here.]