Editing Horus Heresy (section)

==The Tabletop Wargame==
[[Forge World]] produces a line of books and models (in line with the old [[Imperial Armour]] and [[Warhammer Forge]]) to allow players to fight battles from the Horus Heresy, with rules and models for the [[Primarchs]] (both pre- and post-fall, for the Traitors), named characters who were romping around back then and ancient vehicles and machines that would be one off units in 40k armies, being fielded en-mass. Originally an add on system for [[Warhammer 40,000]], it became it's own game with a rulebook after 40k moved on to [[Warhammer 40,000 8th Edition|8th edition]] making it a sort of legacy game for the older style of 40k edition and also meaning the game has become a refuge for fa/tg/uys who don't enjoy 8th/9th edition 40k. Since the game is set during the 31st millennium pretty much all the armies are more archaic versions of their 40k counter parts, with lots of rules and quirks that help differentiate the factions from their future selves, such as legion tactical squads being able to be fielded in 20 man squads representing how much bigger the legions were and [[Daemon]]s not having their gods properly identified (though still having rules for god specific daemons) and having vague unit names to represent the only basic understanding the Imperium had of them. There are no [[xenos]] armies unfortunately (or fortunately depending on who you ask), but all the factions that are in the game are very customisable with a huge array of rules, army types and really good conversion opportunities being able to be brought to the table, especially for Mechanicum, Daemon and Militia & Cults armies. Presumably this came about because GW felt that they just weren't making quite enough money from die-hard marine/chaos players and figured they could literally buy a dump-truck full of gold-plated cocaine each if they made a version of the game that requires only Forge World minis AND thousands upon thousands of them. Still worth it, though.

Following the passing of Alan Bligh and the re-organisation of Forge World as a studio, the fate of this wargame had been seen as a bit precarious. While there were probably more books to cover up to and likely including the Siege of Terra, it seemed increasingly likely that Daddy GeeDubs wasn't keen on letting FW continue writing for this game (or making massive monsters and tanks for the mainstream games) on top of their work on [[Necromunda]] and [[Blood Bowl]]. One only had to look at how gutted the Imperial Armour books became in recent editions to see the writing on the wall. That said, the game had itself a sizeable following, especially after 8th Edition 40K essentially threw out all the crunch fans knew and made something entirely different, predictably leading to reactionary grognards clinging to the remaining flecks of nostalgia.

The game was never fully cancelled though. Though the black books had essentially stopped after Crusade, GW did release '''[https://www.warhammer-community.com/wp-content/uploads/2019/11/HHZone_Mortalis_Rules.pdf Zone Mortalis]''' rules, the Exemplary Battles PDFs mentioned below and more alarmingly, the lead-up to Adepticon 2022 announced that the Horus Heresy wargame was going to see a new edition, now written by the core GW design team. Warhammer Fest 2022 displayed their full intent, with a full box set (filled with plastic Beakies, two new Praetors, a Spartan, and Cataphractii Termies, all in plastic) as well as plenty of other updated models: new support squad weapon kits, reboxed 20-man kits for Mk. III and Mk. IV Marines, plastic Deimos-pattern Rhinos, Sicarans, and Leviathan Dreadnoughts, an updated plastic Contemptor Dread kit, and the brand new [[Kratos Heavy Assault Tank]], a heavy tank placed in between the Sicaran and Fellblade. They've continued to make new models for the game since then (including plans for new models for each of the Primarchs), although it seems Forge World will still be making a bunch of the original models

===First Edition===
'''Book 1: Betrayal''' Forge World starts big, as their first book covers the battles on Istvaan III, in which [[Horus]] sent the remaining loyalist elements of the [[Sons of Horus]], [[Emperor's Children]], [[Death Guard]], and [[World Eaters]] to the surface, ostensibly to rout the anti-Imperial resistance that had taken hold in the capital city, and then fired [[Exterminatus]] torpedoes (of the life-eater virus bomb variety) onto the city to wipe them out.
:Unfortunately for Horus, not everything went as planned; not only did the loyalist Death Guard frigate ''Eisenstein'' escape to the [[Phalanx]] with word of Horus's betrayal, but loyalist elements on other ships were able to disrupt the bombardment and warn the loyalists on the ground that it was coming. Between the disruption, the warning, and good old-fashioned [[Space Marine]] toughness, only a third or so of the landed force had actually died. Horus would have fired another bombardment, but [[Angron]] and his traitor World Eaters jumped the gun and made planetfall; the other traitors were left with no choice but to deploy themselves and destroy the remaining loyalists personally.
:''Betrayal'' contains a [[Great Crusade]] Legion army list (for which we have a [[Warhammer 40,000/Tactics/Space Marines/Legion List‎|tactica]]), and rules for special characters and units from the [[Sons of Horus]], [[Death Guard]], [[Emperor's Children]], and [[World Eaters]] Legions, including their [[Primarch]]s (even [[Fulgrim]], who was not actually at the battle) and several major characters from the book series such as Garviel Loken.

'''Book 2: Massacre''' The infamous Drop Site Massacre is the focus of the next book, where seven Legions are sent to crush Horus’ rebellion, only for four of those to turn on the other three and crush them utterly. The book's storyline is essentially just the ''first day'' of the battle, leading up to the death of [[Ferrus Manus]].
:Massacre contains additional rules for special characters and units from the [[Iron Hands]], [[Night Lords]], [[Salamanders]] and [[Word Bearers]] Legions including their Primarchs and several more major characters from the book series make their debut such as Sevatar, Eidolon, Erebus and Kharn.

'''Book 3: Extermination''' Focusses on the second half of Istvaan V, as well as the Battle of Phall between the [[Iron Warriors]] and [[Imperial Fists]]; and on that note, it includes rules for those two Legions, as well as the [[Alpha Legion]] and the [[Raven Guard]]. It also gives us a complete Mechanicum Army List: the Taghmata.

'''Book 4: Conquest''' Horus Heresy Volume Four is entitled 'Conquest', despite early hints from Forgeworld that it would be about the Battle of Prospero, it instead features Horus' conquest of the Imperium and the [[Skub|"Major"]] battles of this time, which is to say some battle-zones that Forgeworld made up to fill time whilst they worked on the more well known events from the in-universe history. ''(And to be fair, their response as to why Prospero was delayed was because it included four major factions, [[Adeptus Custodes|two of]] [[Sisters of Silence|which have]] NEVER been represented on the tabletop, so required more time to do them justice.)''
:A large portion of the book is given over to running battles in the '''"Age of Darkness"''', which is a variant ruleset used as the default for Horus Heresy games ''(where only Troops usually score, amongst other things)'' and has rules and FOCs for Cityfight missions, rules for running ongoing campaigns, variant rules for mysterious terrain and objectives as well as including unique relics to be taken by the various army lists to add flavor to non-special characters. It also introduces the [[Solar Auxilia]] and [[Imperial Knight|"Questoris" Knights]] (as an AdMech list) armies to play while the modellers take a break from building power armor 24/7.
'''Book 5: Tempest''' The fifth Horus Heresy book covered the Battle of Calth. The rules for the [[Ultramarines]] (including [[Roboute Guilliman]] himself) as well as several warp-corrupted Word Bearer units are brought in alongside a few other new miscellaneous FW releases, including the Deredeo and the new Thanatars. There's also an Imperial Militia (Read: PDF) list that's super-customizable so you can make both loyalist and traitor lists. Also, the MOTHERFUCKING [[Warlord Titan|WARLORD TITANS]] IS IN IT TOO. PREPARE YOUR WALLET.

'''Book 6: Retribution''' Focused on 'Shadow Wars' far from the main fronts of the Heresy, in particular the Shattered Legions - that is, the [[Iron Hands]], [[Raven Guard]], and [[Salamanders]] in their weakened state following their losses in the Drop Site Massacre. But other Legions can also be included, with special rules for the Shattered Legions, Black Shields and a list for Armies of Dark Compliance - mixed traitor Legiones/Militia lists, as well as ten new special characters. It includes Legiones Astartes rules for the White Scars, Blood Angels and Dark Angels, so that players of those legions can start playing properly; however, it does not include special units, characters, or Primarchs for those legions. It also includes Garro and the Knights Errant and additional Mechanicum units and characters, including a new Dark Magos, [[Anacharis Scoria]]. Space Wolves and Thousand Sons will still need to wait for the Prospero book (Inferno, Book 7).

'''Book 7: Inferno''' In <s>Set to be book 3.</s> <s>late 2016.</s> <s>early 2017 (Because FW can't keep to schedule)</s> <s>December 2016</s> February 4, 2017, comes with what many neckbeards are waiting for: THE BURNING OF PROSPERO!!! For those [[Thousand Sons]] players, start saving up so you can play your space Egyptian sorcerers in all their 30k glory. Rules for the Sisters of Silence as an allied detachment and the Adeptus Custodes as a full army list will be present as well.
:Well, it's come, and... it's uninspiring to say the least, with stuff like [[What|Magnus being straight up impossible to hit if he casts invisibility, not to mention pumping out 2d6 destroyer hits at every unit within 18" if he likes]], [[Derp|Custodes captains beating out every Primarch with a rollable 3+ invulnerable save]], some Custodes wargear being straight up [[Wat|left out of the book]] and to cap it all, [[Herp|pictures of tourists in the book ('''twice''') where you'd expect miniatures to be]]. You'd think with such a long development cycle the quality assurance would have been more thorough. Didn't help that [[Alan Bligh]] was likely fairly ill in late 2016, and his death in May of 2017 means the Horus Heresy team now has a big hole in it.

'''Book 8: Malevolence''' After the untimely death of Alan Bligh, this will be the first book with John French behind the wheel after two years of internal re-organizing. Covers the events of Signus Prime and the Chondax Campaigns. It features [[White Scars]] and [[Blood Angels]] including rules for both Jaghatai and Sanguinius, [[Dark Angel Shoulder Pad|making the Lion the only Primarch without rules]]. Introduced as a new army is Daemons of the Ruinstorm, an army of 'unknown aberrant xenoforms' (since this was before the Imperium really understood what Daemons really were) which play quite differently to the Daemons of Fantasy/Sigmar/40K. Also included are 5 new consuls, two new squads, and an entire slew of relics that interact with Psykers and Daemons.

'''Book 9: Crusade:''' Was originally to be called ''Angelus'', though it eventually was renamed to ''Crusade''. It covers the [[Thramas Crusade]] with the Dark Angels vs Night Lords and introduces new Legion-specific units and characters for the Dark Angels, including Dreadwing units and rules for upgrading DA characters to represent any of the six Wings of the Hexagrammaton. Most importantly, the Lion finally has his rules. The Night Lords got revamped rules and some new toys, including a new VIII Legion-specific Terminator squad that [[Derp|isn't the Atramentar]]. Unfortunately leaks have confirmed that the Dark Mechanicum army list has been pushed back to the next <s>book</s> edition. Also has rules for some new Space Marine vehicles, including the Sabre strike tank and the Arquitor Bombard, plus new additions for the Solar Auxilia, Imperial militia, and Chaos cults. Finally released in September 2020, having been delayed due to Nurgle's interference. Remarkable for atrocious fluff like Dark Angel auxiliary fleets usually including [[Gloriana-class_Battleship|Glorianas]], [[Rangdan_Xenocides|"the biggest threat to the existence of Imperium"]] being reduced to 80k Marine casualties in all three campaigns spanning for two decades, Legion recruits retaining their noble status after being conscripted, and many, many more things that would give even Matt Ward a pause. This proved to be the last of the black books for the first edition of the Heresy tabletop, as GW announced a new edition of the game at Adepticon 2022.

====Condensed Lists====
The Istvaan Campaign Legions (ICL) and Legiones Astartes Crusade Army List (LACAL) were initially released as part of the limited edition run of Extermination, but were then later released separately. They are fluff-lite, codex-equivalent books that also included all of the FAQs/Errata up to their release; which unfortunately was still the end of 6th edition so some rules haven't carried over well. ''(eg. [[Lorgar]]'s psychic rules.)''

The LACAL is basically the generic 30k Space Marine "codex", whilst the ICL contains all of the collected rules for the legions from Books 1-3, including their units, characters and wargear. Meaning you can have a cheaper alternative to buying multiple £70+, huge black tomes JUST to play the game. The ICL was continued in the Age of Darkness Legions, which collected everything to book 5, including the errata.

Later came the Mechanicum Taghmata Army List, which contained all the Mechanicum units and army lists mentioned and rearranged them to keep everything on the same page, but lacked the Questoris Knight Army. The Crusade Imperialis Army Lists contain the Solar Auxilia, Imperialis Militia/Warp Cults, and Questoris Knight Crusade army lists.

====Exemplary Battles====
Starting in Fall 2021, GW started publishing a series of free PDFs for the Horus Heresy tabletop which contain mini-campaigns based around battles from the Heresy that have been mentioned in the novels or black books but weren't big enough for a book of their own. These PDFs also include fluff and rules for Legion units that haven't been given any yet, along with photos and conversion tips for said units. These tips boil down to "buy tons of Forge World stuff while you still can", so one could plausibly argue that the PDFs are just ads for FW's overpriced upgrade packs. Still, it's a neat concept and at least they're free. These seem to be leading into the new edition of the game as announced at Adepticon 2022; GW has confirmed that the PDFs released prior to the launch of the new edition have been written to work with both sets of rules. The first wave of articles covered all eighteen Space Marine Legions and ended in January 2023; the second wave will cover their allied units, like Daemons of the Ruinstorm, Chaos cults, and Solar Auxilia.

*'''''[https://www.warhammer-community.com/wp-content/uploads/2021/09/Xwccsydzg8YpDsho.pdf The Battle of Pluto: Hydra's Devastation]''''': Focuses on the Alpha Legion's invasion of Pluto, as seen in ''Praetorian of Dorn'', and provides a scenario for Imperial Fists vs Alpharius' sneaky sneks. Also has rules for the Huscarls, Dorn's elite bodyguard, which make them into Phalanx Warders on steroids.

*'''''[https://www.warhammer-community.com/wp-content/uploads/2021/11/9eA3ZYnzr5tXbxjX.pdf The Defence of Sotha: Aegida's Lament]''''': Focuses on the Night Lords' raid on Sotha and the near-destruction of the Ultramarines Aegida Company while attempting to hold Sothopolis. The Atramentar ''finally'' get their tabletop rules and also are spotlighted in the fluff, which concludes with them [[Internet Troll|murderfucking their own commanding officer]] because he was getting too uppity for the other Night Lord officers' liking.

*'''''[https://www.warhammer-community.com/wp-content/uploads/2021/11/NUTJvW4qx8d08Fkr.pdf The Siege of Hydra Cordatus: Sundering of the Cadmean Citadel]''''': Imperial Fists vs. Iron Warriors brawling it out on the ruined world of Hydra Cordatus. Includes rules for the IV Legion's Dominator Cohort, Perturabo's former bodyguards who got fired and replaced with the Iron Circle after Phall. Hilariously, they are so salty about this that they have Hatred (Cybernetica Cortex) unless you take them as Pert's retinue.

* '''''[https://www.warhammer-community.com/wp-content/uploads/2021/12/fcMVfgBlCyDHmejD.pdf The Battle of Armatura]''''': World Eaters vs. Ultramarines on the war world of Armatura, as seen in ''Betrayer''. Includes rules for the XII Legion's Red Hand Destroyer squads, who can take Caedere weapons like meteor hammers and excoriator chainaxes in addition to all the usual Destroyer nastiness and ''must'' declare a charge whenever able if they're within 12" of an enemy unit at the beginning of the Assault phase.

* '''''[https://www.warhammer-community.com/wp-content/uploads/2022/01/mouvfePNquxVdprP.pdf The Battle of Perditus: Umbral-51]''''': The Death Guard are trying to [[Ork|loot]] galaxy-wrecking archaeotech and the Dark Angels mean to stop them. Iron Hands and Mechanicum are there too, and the mission pack has rules for rampaging battle-automata trying to kill the Spess Mehreens so the techpriests can go back to worshiping their doomsday devices in peace. Includes rules for units from both sides: the Order of the Broken Claw and the Mortus Poisoners. The Broken Claw are Inner Circle Knights who get bonuses against Monstrous and Gargantuan Creatures and daemons, representing the fact that they were the I Legion's specialized Rangdan-killers during the Xenocides. The Mortus Poisoners are Destroyers who can swap their bolters for flamers with chem-munitions for free and one in every five can swap their bolt pistol for a heavy flamer with chem-munitions for 20 points ([[Derp|that's right, their '''bolt pistol''', not their bolter, blame FW editors]]), and can be taken in units of 15 for when you just want the table to burn.

* '''''[https://www.warhammer-community.com/wp-content/uploads/2022/02/iIVebnZrYRFbaDGH.pdf The Battle of Calth: Underworld War]''''': Smurfs and Word Bearers duking it out in Zone Mortalis missions representing the underground battles fought after Calth's surface was trashed in ''Know No Fear''. Includes rules for the Ultramarines' Nemesis Destroyer squads, aka Guilliman's least favorite sons. Instead of dual bolt pistols, they get bolters with specialist ammo that gives them Assault 2 and Rending and they can take weapons usually reserved for Breacher and Support squads. Kinda weird, but makes sense given the XIII's "tactical flexibility" schtick. No jump packs, though.

* '''''[https://www.warhammer-community.com/wp-content/uploads/2022/03/H6ygklXe9Fv2FwRe.pdf Battle For Kalium Gate]''''': Emperor's Children and White Scars get their turn, fighting over a huge void gate as the Scars try to get back to Terra in time for the big party. Has rules for new units from both sides. The III Legion gets the Sun Killers, Heavy Support squads that only use lascannons, multi-meltas, volkite culverins, and plasma cannons [[Meme|because they're elegant weapons from a more civilized time]]. The White Scars get the Karaoghlanlar, or Dark Sons of Death. Aside from sounding like a Welsh person choking on something, they're jump-pack Destroyers who don't get phosphex or missile launchers and trade one bolt pistol for a chainsword, but can be taken as a retinue for a Stormseer with a jump pack. They also have a rule that lets them autofail Sweeping Advance rolls in exchange for performing a spooky ritual that forces enemy units within 6" to pass an Ld test or suffer -1 WS next turn.

* '''''[https://www.warhammer-community.com/wp-content/uploads/2022/04/AmPdr3yMZbvggCND.pdf The Breaking of the Perfect Fortress]''''': Raven Guard storming the III Legion's Perfect Fortress on the world of Narsis, previously mentioned in ''Deliverance Lost''. Includes rules for the Deliverers, Terran-born Raven Guard who were trained under Horus and still prefer to use Terminator armor and shock-assault tactics. They're Stubborn and get teleportation transponders for deep-striking, but their main rule is Corax's Shame, representing the fact that Corax wasn't fond of his brutal Terran sons. They get +1T against attacks that cause Instant Death and cannot be deployed within 18" of Corax, nor can he ever join them. If you take Deliverers as part of a traitor force, they instead gain Hatred against Corax.

* '''''[https://www.warhammer-community.com/wp-content/uploads/2022/06/TLbrp4me5GEfL37Q.pdf The Scouring of Gilden's Star]''''': Word Bearers vs Blood Angels fighting over a ''Hamlet'' reference last seen all the way back in 1989. Has rules for the Word Bearers' Procurators, basically assault squads led by evil Apothecaries who [[Blood Ravens|steal gene-seed]] and desecrate corpses to summon daemons. They give boosts to friendly psykers with the Harbinger of Chaos, Diabolism, and Anathemata disciplines and award an extra VP every time they Sweeping Advance an enemy unit.

*'''''[https://www.warhammer-community.com/wp-content/uploads/2022/07/6i9CeSwKmbWmzac4.pdf The Battle of Trisolian: Vengeful Spirit]''''': Taking a page from the ''Wolfsbane'' novel, this portrays the part of the [[Battle of Trisolian]] when the Space Wolves broke into Horus' flagship during Russ' attempt to kill Horus before he reached Terra. Introduces the Space Wolves' Jorlund Hunter Pack, Assault Marines that can temporarily supercharge their flamers, and the Sons of Horus' Chieftains, an elite retinue of junior officers who specialize in hunting down characters.

*'''''[https://www.warhammer-community.com/wp-content/uploads/2022/09/3mVvZrTG9XOWeVxv.pdf The Axandria IV Incident]''''': Imperial Fists, Custodes, and Sisters of Silence raid a Thousand Sons repository world not long before the Siege of Terra, and the Thousand Sons actually score a win this time by evacuating their data stacks before the loyalist forces can trash them. Includes rules for Numerologist Cabals of the Order of Ruin, Thousand Sons Techmarines and tacticians who used divination to generate battle plans and predict enemy movements. The Numerologist gains a special psychic power that gives him a geo-locator beacon and boosts the BS of two friendly Thousand Sons squads if he passes a psychic check. He also gets a bubble-wrap rule that prevents him from taking any wounds no matter what until all his bodyguards are dead, unless he accepts a challenge.

*'''''[https://www.warhammer-community.com/wp-content/uploads/2022/11/tY1xCtj3G3KDp1KS.pdf The Battle of Nyrcon City: Visions in the Flames]''''': Alpha Legion fighting the Salamanders on Beta-Garmon prior to the Titandeath. Has rules for Salamanders Adherents, berserker madlads who pack combi-flamers and heavy flamers for extra burninating power, and the Alpha Legion's Effrit Disruption Cadre, Recon Marines from Omegon's posse who get shotguns or Nemesis bolters and a special piece of kit that reduces enemy Ld and interferes with nuncio-voxes and augury scanners.

*'''''[https://www.warhammer-community.com/wp-content/uploads/2023/01/AJe5dSaQjlJaFQb2.pdf The Death of Canopus]''''': The final Exemplary Battle in the first wave. Blood Angels vs. a bunch of Iron Hands with severe trust issues after the [[Drop Site Massacre]], and then both of them against the Sons of Horus after they show up. Includes rules for the Ofanim Court, the shadowy coterie of Blood Angels who policed those who fell to the [[Red Thirst]], and the Morlock Terminators, Ferrus' bodyguard. The Ofanim are basically assault marines with juiced-up power swords who specialize in killing other Space Marines, while the Morlocks get graviton guns and either Chosen Warriors or Preferred Enemy (Emperor's Children) depending on if Ferrus is alive or not.

*'''''[https://www.warhammer-community.com/wp-content/uploads/2023/03/JXRAKYvl3BrGbGjD.pdf The Burning of Ohmn-Mat]''''': A Sons of Horus warlord lays siege to the forge world of Ohmn-Mat in order to perform some profane rituals. Though besieged by both the local Taghmata and a surprise force of Iron Hands led by a former librarian, the ritual eventually succeeds and daemons are summoned, including [[Samus]], before the planet gets rigged to explode in a pyrrhic victory. Includes rules for a Bound Daemons detachment, clearly a preview for what is to come for the Ruinstorm Daemons.

===Second Edition===
The first two books for the new edition of the tabletop were revealed at Warhammer Fest 2022: the '''Liber Astartes''' and the '''Liber Hereticus'''. These are basically updated and combined versions of the LACAL and ICL books. Both books contain the rules for all non-Legion-specific units, while the Liber Astartes has the rules for the loyalist legions and the Liber Hereticus has the rules for the traitor legions, including their Primarchs, unique units and wargear, Rites of War, Warlord Traits, and faction abilities. The '''Legacies of the Age of Darkness''' PDF contains the rules for vehicles, units, and characters who either never had models or whose models are now out of production, including most of the Legion-specific special characters, Castraferrum Dreadnoughts, the [[Crassus Armored Assault Transport|CRASSUS ARMOURED ASSAULT TRANSPORT]], and all of the Baneblade variants. Later leaks, which Warhammer Community would confirm, revealed that there would also be books for the Mechanicum ('''Liber Mechanicum''') that would contain rules for the Taghmata, Knights and Titans as well as a book for the Custodes, Sisters of Silence, Solar Auxilia, and Divisio Assassinorum ('''Liber Imperium'''). Daemons of the Ruinstorm and Imperialis Militia/Warp Cults will get downloadable Legacies lists, and according to the Legacies PDF the Knights-Errant and Blackshields are being made into full factions. They will also continue to release the Exemplary Battles series; the previously released PDFs got a separate update PDF in order to work with the new edition.

The general tactics page can be found [[Age of Darkness-Warhammer 30k/2.0 Tactics/General Tactics|here]].

The core rules have been drastically modified with the addition of "Reactions", which make gameplay more dynamic. In addition to basic reactions such as Overwatch that can be taken in response to the opponent's actions, each Legion now has an "Advanced Reaction" that is more powerful but requires more specific conditions to work. Furthermore, USRs have been rewritten to be more granular (e.g. Bulky, Very Bulky, and Extremely Bulky are now Bulky (X), where X is is how many models that unit counts as for the purposes of transport capacity) and the Psychic Phase has been removed in lieu of the pre-7th edition manner of resolving psychic powers.

Warhammer Fest 2023 saw the series finally get back to campaigns after getting most of the armies out of the way, with the first being '''Siege of [[Cthonia]]''' and the war the Sons of Horus and Imperial Fists had there.