Changes

The [[Akum-Sothos Cluster]] had been brought to compliance by the [[Luna Wolves]] in the opening years of the [[Great Crusade]], but its people had since fallen to mass-psychosis and violently revolted against the authority of [[Terra]]. It was determined that a [[Xenos]] parasite which that matured within the eye sockets of its host had been behind the riots. The parasites gained rudimentary control of their hosts as they matured and formed what amounted to an alien gestalt cabal of primary hosts dubbed the [['Unsighted Kings']]. Newly ascended [[Warmaster]] [[Horus]] refused to see a cluster of worlds he himself had once conquered slip from the [[Imperium]]'s grasp, so he vowed to retake the Cluster no matter the cost.{{Fn|1}}

After conquering the outer worlds of the Cluster in a matter of weeks, Horus called a council of his brother [[Primarch]]s. He called for the Raven Guard to make a frontal assault onto on the guns of the defenders of Gate Forty-Two. Their primarch, [[Corax]] argued against this waste of resources and squandering of his warriors' lives, countering with a strategy of his ownstrategy. He proposed that his Legion should draw off enemy forces in a series of feints, allowing the three other Legions to overwhelm the defenders who remained at the Gate. However [[Perturabo]] suggested that Corax was simply seeking to avoid battle, labeling him a coward. The two nearly came to blows, and ; only the intervention of [[Leman Russ (Primarch)|Leman Russ]] prevented bloodshed. However , the Space Wolves Primarch told Corax to heed Horus' plan, as he had been the one whom [[Emperor of Mankind|the Emperor]] himself had put above any of his brothers. Reluctantly, Corax conceded. He committed many of his [[Terra]]n-dominated [[Space Marine Company|companies]] to the frontal assault, in particular those whose [[Space Marine Captain|Captains]] appeared the most willing to support Horus' strategy.{{Fn|1}} Corax had long maintained a disfavor with his Terran officers, mostly due to their use of brutal terror tactics before his arrival.{{Fn|2}}

The following assault that followed was hailed as the Legion's darkest hour, a grim honour honor that saw entire [[Assault Marine|Assault]] companies decimated in the face of heavy enemy defenses. Corax himself led the bloody attack that saw Gate Forty-Two finally taken. The Luna Wolves, Space Wolves, and Iron Warriors moved into the Unsighted Kings fortress soon after. Bitterly for Corax, the glory of slaying the Unsighted Kings themselves went to Horus and his Luna Wolves. But despite the victory thousands of Raven Guard, most of them Terran-born, had lost their lives.{{Fn|1}}

The effects of the battle were far-reaching for the Raven Guard. Its numbers were sorely depleted after the battle, and : the Legion now numbered only 80,000 Marines after the battle. Corax removed his forces from Horus' command, bitterly swearing to never serve alongside the Warmaster again.{{Fn|1}}

Another effect of the battle was that the Terran-born officers of the Raven Guard had largely been killed. Many of these officers had served under Horus at one point and some suspected their loyalties to their true Primarch was lacking. Thus the battle allowed Corax to consolidate his power over the Raven Guard, and erased the Luna Wolves ' influence over the Legion.{{Fn|1}}