Horus Heresy Aftermath
Dorn's VengeanceRogal Dorn's grief was immense in the aftermath of the Horus Heresy. Until that point, Dorn had been true, noble and enduring, but now he became an avenging son dressed in the black of mourning. Whereas other Legions, such as the Ultramarines, dedicated themselves to rebuilding the Imperium, the Imperial Fists launched a crusade against the Traitor Legions, hunting them down and levelling fortress after fortress. Yet the Legion was still cognisant of its broader role as it lent itself to direct calls for assistance by Imperial worlds and institutions more so than other Legions during this period. Nonetheless, Dorn was absent from the highest councils of the Imperium until he returned to Terra upon being summoned by Roboute Guilliman to be presented with the Codex Astartes.2c
Codex Astartes CrisisDorn initially rejected the Codex Astartes and enmity developed between him and Guilliman. Dorn called Guilliman a coward, citing his lack of participation in the defense of the Imperial Palace. Guilliman accused Dorn of being a traitor for refusing the Codex. This enmity quickly involved other Space Marine Legions and a rift developed, Leman Russ of the Space Wolves and Vulkan of the Salamanders stood by the Imperial Fists, while Jaghatai Khan of the White Scars and Corax of the Raven Guard supported the Ultramarines. A second civil war appeared likely when the Imperial Fists strike cruiser Terrible Angel was fired upon by the Imperial Navy in connection with Codex crisis.15a However, Dorn ultimately relented after spending seven days meditating in the pain glove. There, he concluded that the Legion could no longer serve the Emperor who had been and must serve the Emperor who was, which involved accepting the new order of which the Codex was a part.2c
The Iron CageIt was Dorn's decision that the Legion would symbolically enter into the pain glove together and emerge according to the Codex Astartes. This opportunity presented itself in the battle that became known as The Iron Cage. The Imperial Fists had largely dismantled the Iron Warriors empire in their campaigns immediately after the Heresy. Upon discovering the Eternal Fortress, a twenty square mile fortress constructed by the Iron Warriors, Dorn, fuelled by his enmity towards Perturabo, committed the entire Legion to its assault.2c
Perturabo and his Legion were masters of defence and siege in their own rite and had designed the Eternal Fortress as a trap to ensnare the Imperial Fists. Ceding further advantage to the Iron Warriors, Dorn led the assault without his customary care in planning and preparation. What ensued was a near massacre. The Imperial Fists’ formations were broken, reduced to fighting with combat knives battle-brother by battle-brother in half flooded trenches with their ammunition expended.2c
Yet, the Imperial Fists endured and the Iron Warriors were unable to finish them, lacking the faith to make the ultimate sacrifice that victory demanded. The Ultramarines then intervened, driving off the traitors.2c
ReorganisationCleansed by their sacrifice, the Imperial Fists immediately began their reorganisation2c with the fully hardened, veteran force that remained.2d For the next two decades, the newly formed Chapter went into retreat in order to master the tenets of the Codex Astartes. The Chapter has since assumed a place alongside the Ultramarines as exemplars of the Codex.2c Importantly, however, the Chapter retains its previous special ability in siege warfare, urban warfare and defense, although preference is given to aggressive rather than defensive options. 2d This is particularly the case with siege warfare, as "The Imperial Fists are renowned siege masters par-excellence." As siege masters, the Chapter is noted for both "grimly defending fortifications against innumerable foes, or storming valiantly against bastions," therefore specializing in both defensive and offensive sieges. 26 The Chapter also maintains its own martial tradition as codified in the Book of Five Spheres as an addendum to the Codex Astartes.
As part of their reorganisation, the Imperial Fists participated in the Second Founding, christening the Soul Drinkers, Black Templars, and Crimson Fists. The Legion’s most fanatical battle-brothers composed the Black Templars while the more level headed members founded the Crimson Fists.2d It is noted that the Imperial Fists successor Chapters form a particularly tightly knit brotherhood of Space Marines, three of which are known to participate in the Feast of Blades, including the Imperial Fists. 16
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