"The Iron Warriors had been close to breaching the defences of the Imperial Palace but had been thwarted by Horus` death. Afterwards their empire was dismantled by the Imperial Fists by virtue of overwhelming superiority of numbers." You need a history lesson. You're right about it being last ditch, but that's about it. Why was the Venegful Spirit able to be boarded at all? Because Horus lowered the shields in desperation; it was a last ditch gamble by Horus, because he knew the rest of the Loyalist Legions (namely the blue, nigh endless numbers of the UM Legion) were en route and essentially around the corner. He knew the Emperor would take the bait. And his gamble almost worked, but the gamble was his, not the Emperor's. If you think the Traitor Forces would have made any headway in the Imperial Palace had the Emperor, Sanguinius and Rogal Dorn stayed there defending it, you're kidding yourself. But even then, see the above quoted paragraph. The walls were held vs. the Iron Warriors. That's from their own IA:IW article. The Iron Cage was not a massacre; it certainly began as one, but then in the end, it turned into a bloody stalemate which was eventually broken by the Ultramarines. Regardless, how is 400 Marines killed out of an entire Legion "within a whisker of completely destroying" the Imperial Fists? It's not. Had the battle continued, the two forces would have likely annihilated each other. Furthermore, the Iron Cage was the last battle after a series of Iron Warrior defeats; their empire was dismantled by the Imperial Fists after the Heresy. Again, see above. If the Imperial Fists had been within a "whisker of being destroyed"...well, where did the thousands of Black Templars and Crimson Fists and Excoriators from come then? They were all originally, to a man, serving Imperial Fists.
Do I? Under Perturabo's command, a combined assault was launched that finally saw a traitor breakthrough. Perturabo combined an underground assault in tunneler drills with a pinpoint Chaos titan Macrocannon bombardment. The walls of the Emperor's Palace finally broke, unleashing a flood of traitors into the inner courtyards of the Palace. A massive labyrinth of hallways, complexes, courtyards, and buildings, fighting in the outer palace was room-to-room and saw heavy casualties inflicted on the Traitors. Moreover, the inner sanctum of the palace had been heavily reinforced and in the enclosed spaces Traitor titans and heavy war engines became easy prey for the well-prepared loyalists. The Adeptus Custodes made a fierce counterattack at the inner gardens of such brutal efficiency that none of the traitor horde could initially stand against them. However in the end, the Titans of the Legio Mortis proved decisive in a traitor breakthrough. In addition traitor numbers were too great and even the Custodes were overwhelmed. - Source: Index Astartes IV That isn't consistent with the walls being held. The core of the Palace was still in Loyalist hands, but by that point in the battle, it's pretty much the only thing that was. The details and rationale of Horus lowering the void shields on the Vengeful Spirit are disputed in the lore (intentionally, IMO), but it was undoubtedly an attempt to bring a swift resolution to the final stages of the conflict by inviting the Emperor, Sanguinius and Dorn to risk all - which they did, with devastating long-term consequences for both sides. You've slightly, but crucially, misinterpreted part of that. 400 marines wasn't the IF death toll, it was the number of unrecovered IF wounded and slain at the end of the battle. Bearing in mind that 400 astartes represents nearly half of a post-Heresy space marine chapter, this is a phenomenal number to have had to leave behind to the tender mercies of your mortal enemies. Sacrificing their geneseed to Chaos is what prompted the Dark Gods to elevate Perturabo to Daemonhood. The numbers killed over the course of the battle to arrive at that figure would have been ruinously high. The claim that the Imperial Fists took 19 years to recruit and recover, returning as 3-4 cut-down chapters, may be apocryphal. It is, however, widely cited by both sides and Dorn may have known exactly what the likely outcome was when he attacked Perturabo. It's also worth bearing in mind the Iron Cage followed the heavy IF losses during the destruction of the Retribution Fleet at Istvaan, estimated at 10,000 (!) Imperial Fists, the battle of Phall (not stated, but a number of Polux's ships were annihilated), Mars (50% casualties of 4 veteran companies - size not stated, but likely a minimum of 2,000) and Terra (unknown, but likely not pretty). The Imperial Fists were in no real state to deploy themselves in the Great Scouring to the extent they actually did - that Dorn insisted they take one of the most leading roles is evidence that he'd become a bit unhinged in the immediate aftermath of the Emperor's death. No shame in that, mind - several Primarchs on both sides lost their marbles before or after the Heresy, and he did at least recover his wits once the bloodlust had passed. That the Fists achieved so much and so swiftly in the Scouring despite all this is absolutely remarkable, and much to their credit. But it was also nearly their death sentence. It's fair to say that the Iron Warriors didn't walk away from the Iron Cage unscathed, but although the battle has propaganda flowing from both sides, the idea that it was an Imperial victory in any meaningful sense except that Perturabo withdrew is very hard to square with the above. There is, however, a lot of common understanding about what happened up to the Ultramarines involvement... By the sixth day of the battle, the Imperial Fists had been reduced to fighting a series of individual engagements that could not hope to penetrate the Iron Warriors' layered defences. Rogal Dorn was forced to intervene personally a number of times to turn back assaults that would have slaughtered the remaining Fists. The Legion's captains pleaded with their Primarch to organise a breakout and retreat from the Eternal Fortress' lines, but Dorn refused. Ever loyal, the Imperial Fists resigned themselves to die fighting beside their Primarch. After three weeks and six days, Ultramarines intervened, driving off the Iron Warriors. Unable to defeat both Legions combined, Perturabo concentrated his forces on denying the Imperial Fists withdrawl and disrupting their ability to collect their dead and wounded battle-brothers, of which 400 were never recovered The Iron Warriors succeeded in inflicting overwhelming casualties but failed to destroy their bitter enemy totally. - Sources: Index Astartes I (Iron Warriors), Index Astartes II (Imperial Fists)
I thought about buying some Heresy novels. But then I figured I'd just wait for some more posts. It'll take me longer to read, but hey, free!
Chaos took over the Palace ? No, The Iron Cage was a trap. Just a trap to eliminate the Imperial Fists. because, all the fortresses of the Iron Warriors were falling one after the other ... The Iron Warriors are weak and cowardly, they have set up this trap to exterminate the Imperial Fists, not to fight (the Iron Cage was only a dead zone). And in the end, they failed. There were numerous losses, but the Imperial Fists survived (Surviving a extermination, it is rather well).
Considering the fluff has changed alot over the last few years means both could be wrong. We need to wait til these events in the HH are finished. This is pretty much just ''he said she said'' situation, On one side we have the ''they newer breached the palace'' and on the other ''they breached the palace around the same time as horus lowerd the shields on his ship'' Until the writers finish the siege of terra book's both are right and wrong at the same time (damn you tzeentch)
In the new lore it's stated that the Iron Cage was no longer a trap but in fact it would be the death of the two legions fighting each other, until the Ultramarines showed up that is. I can't wait until we get a book about it, will be a fantastic read.
So they re-write the Horus heresy era with the novels? we are going to get badass triple book story of the siege on Terra?
Sneak peek at the video I'm currently making for the Space Marine stuff View: https://youtu.be/x5YjkZoPzSQ