Horus Heresy: Warzone Xyphos

The Xyphos Sub-sector

Welcome to Xyphos, a sub-sector of our own creation set in the galactic south-west, not far from Cadia. We thought it would be fun to carve out a corner of the Horus Heresy for us to weave a narrative amongst all our games. Away from cataclysmic events such as Isstvan, Calth and Signus Prime we can direct the narrative how we want.

The Horus Heresy was a time for unnamed individuals to stand amongst titans and countless heroes and villains were forged who might otherwise have been left in obscurity. It is time for your praetors, lord marshals and archmagi to shine!


Deep in the Segmentum Pacificus the sub-sector of Xyphos has so far escaped the worst of the Horus Heresy. The area is home to seven systems, at least 54 worlds and countless billions of souls. A veritable paradise amidst a galaxy aflame, the sub-sector has considerable resources to be used for the war effort.

When news of Horus’ betrayal first spread to the Xyphos sub-sector, Governor Horatio Octavian quickly affirmed the Archadian system’s loyalty to the Emperor and the other populated systems followed their lead. The sub-sector geared for total war: forge world Hephaiston’s output multiplied, Eremus’ armouries were filled with countless weapons and ammunition whilst the ports above Helios IV buzzed with warships.

Several shattered remnants of the betrayed legions fleeing Isstvan V managed to make their way to Xyphos and were welcomed by the loyalist systems. Sheltered, untouched and well stocked, Xyphos was a formidable asset in support of the loyalist war effort.

This was about to change, as the Eye of Horus turned its lidless stare to the sub-sector and let slip its hounds of war…

Initial traitor advance into the Sub-sector


The sub-sector is currently loyal to the Emperor, with various key systems declaring for Terra as soon as they heard news of Horus’ betrayal. The Warmaster cannot allow this and has sent several forces under his command to secure the sub-sector or, if not possible, raise it to ashes.

XXII Millennial, Emperor’s Children, were the first traitors to arrive and secured quick victories in the North by taking the Zeugan and Perditian systems at a lightening rate by avoiding the central systems that remained unwaveringly loyal. The Emperor’s Children demanded compliance from all planets before them and eradicated anyone who refused. The hive world of Persepolis was one such world that refused to bow to Horus and now lay a smouldering ruin as a statement to all those who defy the Warmaster. Yet the loyalists did not respond to these attacks, refusing to be drawn out to terrain not of their choosing. They did not have the resources to protect every planet and amassed their forces to defend the key systems and planets in the core. Now the traitors arrived en masse though, it was time for the loyalist counter-attack.

Defence of the Dread Ring

The Dread Ring is the name given to the chain of orbital platforms, monitoring stations and defence silos that protect Ieriche. As Ieriche sits at one end of the only stable route into the sub-sector, the Dread Ring handles most of the traffic to Xyphos. This means it is well protected with an entire cohort of Solar Auxilia (the 566th) and the Grand Cruiser Beck’s Oath. Such a force was enough to defend the Dread Ring from an attack by pirates, Xenos abominations or any other raiding party that might threaten Ieriche in normal circumstances.

But these were not normal circumstances, and they were not prepared to fight astartes.

When the first traitor ships materialised in the system, the Dread Ring was put on full alert. Auxiliaries rushed to man pre-prepared positions and gun-servitor targeting routines were locked onto the Emperor’s Children ships. With the might of Beck’s Oath supporting the orbital platforms Tapé-al, commander of the Dread Ring, had formidable firepower and was determined to make the traitor’s pay.
As the traitor fleet pulled into range, disaster struck. Orbital Station Noctra suddenly turned its guns on Beck’s Oath and opened fire with everything. Not expecting such a close-range barrage from a supposed ally, Beck’s Oath went supernova, destroying several other stations in the resulting explosion.

It was in this chaos that the Emperor’s Children attacked. Despite fighting valiantly, the men of the 566th were no match for a full chapter of astartes and particularly not with their biggest asset destroyed. The outcome was inevitable and one by one the Dread Ring fell silent. It was the first, but not the last, casualty in the war for Xyphos.

It was not until the Scouring that investigations were launched into the loss of Beck’s Oath and the destruction of the Dread Ring. These investigations raised more questions than they answered. For example, why did the shields on Beck’s Oath fail moments before Noctra’s barrage struck, why had four naval ratings failed to appear at their designated posts that morning, or was the theft of a dozen uniforms from Orbital Station Kels some weeks earlier related. A potential answer lies in the only pict-record recovered from Noctra before its self-detonation. Although the pict is grainy, it is possible to make out two figures in teal-coloured astartes plate operating a console. We can only guess how long the traitors had been in the sub-sector, but the presence of Alpha Legionaries suggest it was far longer than we first thought.

The Eagle and the Raven

Not long after the Emperor’s Children fleet arrived in the sub-sector with deliberate pomp and circumstance, another smaller fleet translated into real space on the outskirts of Ieriche. This was the Aris Irae and its escorts, belonging to the Raven Guard. They had come with only one thing on their mind: vengeance.

It was on the plains of Isstvan V that Shadow Captain Kraai of the Raven Guard and Lord Legate Antigonus of the Emperor’s Children first met. Fleeing the massacre, the Raven Guard were harried as they attempted to get off world. Antigonus’ 22nd Millennial were one of countless hunting parties chasing down surviving loyalists for sport. Fielding many jetbikes, they were able to traverse the rough terrain of Isstvan V easily and culled legionaries with joy. Horrified and enraged at what had become of his former battle-brothers, Kraai set out to make them pay. An exceptional commander, Kraai began tracking the Emperor’s Children and by luring them into ambushes started reaping his own tally of kills. The hunters soon became the hunted. Antigonus and Kraai engaged in a deadly game of cat and mouse over the Raven Guard’s 98-day retreat. The two commanders developed a bitter hatred of the other and each swore that they alone would kill their mortal foe.

Not long after the Raven Guard escaped, Antigonus also left to re-join his legion. With the one opponent gone who he felt matched him, he had little reason to stay on the blasted plains of Isstvan V.

After the Drop Site Massacre on Isstvan V the remaining legionnaires of Kraai’s II Battalion were reforged into the 8th Talon by Corax. They were tasked with hunting traitors and disrupting their march to Terra. Kraai’s Talon encountered the XXII Millennial several times in this undertaking, and the praetors often met in personal combat. Although unable to deal the final death blow, both have grievously wounded the other. Antigonus gained the nickname ‘Twice Scarred’ because of his facial scars caused by Kraai’s ravens talon, first on Isstvan V and then again on Kardiv Prime.

Although bitter, theirs was but one rivalry that developed during Horus’ rebellion. Breaking bonds of brotherhood forged in war often leads to a depth of hatred that causes the deaths of countless innocents as collateral. Other rivalries that would play out in Xyphos include between Chapter Master Cato Valerianus and Battlemaster Rhommal, Sergeant Tiamat and Chaplain Sol Grathos, or Hipparch Anthame and Commander Ghaltra.

%d bloggers like this: