Whilst the Emperor’s Children, Raven Guard and Salamanders represented the bulk of the Legiones Astartes presence, detachments of marines and even individual battle-brothers from all the legions were present during the war in Xyphos.
The following report prepared at the request of Ghe Ven Ha, Supreme Grand Treasurer of the Xyphoneian Ministry for Logistic Affairs, in the years following the conclusion of the Great Heresy lists those confirmed sightings of Astartes, though likely many other groups also participated in the sub-sector war but simply left no eye witnesses.
Dark Angels
Before being folded into the 216th Expeditionary Fleet, the Saoghal siege units had fought alongside the 6th Chapter of the Dark Angels. Whilst the Dark Angels were eventually recalled to their legion, pict-recordings indicate that three Astartes remained with the Saoghal infantry well into the war in the Xyphos sub-sector. No official record can be found within the 216th Expeditionary Fleet’s order of battle and their presence is of note given the troubles caused by the Fleet’s initial status as a non-Astartes, secondary line formation.

This author can only speculate for the reasons for withholding their presence, but one clue is that the Dark Angels appeared most frequently on Eremus. A closely kept secret outside of Expeditionary Fleet High Command was that the seemingly benign world of Eremus hosted a significant subterranean weapons vault. It is possible that these Dark Angels were assigned to watch over Eremus without drawing attention of a full garrison. Given the lack of any other significance to the world of Eremus, it this author’s most plausible reason.
Iron Warriors
Whilst the main traitor fleet moved on after the initial conquest of the Zeugan System, 216th Expeditionary Fleet Intelligence Corps reports indicated a number of detachments were left behind to secure a long term traitor foothold in the sub-sector. The focus of this effort seems to have been on Persepolis, where the Sushan Line acted as a ring of steel around the capital hive. Already a formidable defence network, it appears to have been fortified considerably by the traitors.
The below pict recording shows an unidentified member of the Iron Warriors legion directing several members of the Vashdarii in their back-breaking work establishing a supply dump. The Iron Warriors moreso than any other legion had millions of mortals whose lives were entirely at the whim of their post-human tyrants.

Although it is not possible to identify the specific legionary given the Iron Warriors‘ disdain for personal ornament, the pict does reveal some information about them:
- He wields a Sagaris which suggests he is a native of Partsus, which was an uncommon recruiting world for the IV Legion.
- His green kneepad suggests he was a member of the 444th Grand Company, which conflicts with numerous accounts of the 444th Grand Company fighting in the galactic north-east. Several reasons are possible for this. It could be part of a wider false-flag scheme to exaggerate traitor numbers in Xyphos, this legionary may simply be on assignment to another Grand Company, or he could be a lone survivor spat out by the chaos of the war who ended up being folded into another unit.
- He is likely a member of an augur command and control squad based on his modified Mark III armour with a non-standard backpack. Fitted with additional battery capabilities, this allows a better integration with the logistic nexus and tacticae screens required to operate chapter-level warfare. Being so power hungry, such devices are usually reserved for command level vehicles such as the Damocles Rhino or Leviathan command vehicle. As Iron Warriors preferred to use a “portable” version which necessitated extra power provided by the user.
White Scars
Records indicate that Khoisan Hugalu was present during the Chogoris campaign. His cruiser was ambushed by an Alpha Legion kill team after being scattered by a Warp Storm. Khoisan was the sole survivor due to a last minute escape pod jettison. He landed on Cal X, a loyalist frontier world, and decided to do whatever he could to return to his gene father. Records indicate his drawing a number of idiosyncratic imperial army units to his side after re-commissioning a Sword Frigate.

Whilst studying V Legion records is difficult due to the opaque cultural practices of Chogoris, the following excerpt was found on a discarded dataslate and appears to be an account from Khoisan himself:
My name was Eirche of the Greenol. I fought alongside the Emperor on Terra and a dozen other worlds. I was a pathfinder, a raider, a slayer of demagogues. I was a Star Hunter.
Eirche of the Greenol died at Quan Zhou.
Khoisan Hulagu was born during the Blooding. I scared my face as the Talaskar do and swore my oath to my gene-father. I am the bow, the mantis warrior, the dawn’s fire. I am of the Ordu Jaghatai.
Khoisan and his detachment ended up in Xyphos, where they were incorporated into the loyalist army. However, unlike other Astartes units that were dispatched to fight the traitors front on, Khoisan put his pathfinding skills to the test. He performed a key role in identifying other routes in and out of the Xyphos Sub-sector other than the Freeman Passage.
Alpha Legion
The presence of legionaries from the XX legion was disputed for much of the Heresy, with reports of marines in shadow armour on Hephaiston dismissed as misidentification of other, loyalist units. However, following a sub-sector wide data audit during what was to become known as the Scouring, a number of instances of Alpha Legion forces were corroborated. This includes the grainy footage on Orbital Station Noctra & the catastrophic opening blow on the defences around the Freeman Passage. It is still unclear what the Alpha Legion was doing in Xyphos, or how many marines were present. Most accounts of the Alpha Legion show them from the main fronts, and often in seemingly contradictory operations.

The above pict recording shows Imrik of the Salamanders 13th Chapter fighting an unidentified Alpha Legionary. This author presumes that must be a high ranking official based on the armour’s ornamentation. However it is impossible to say for certain given the Alpha Legion’s preference for misdirection and the absence of any other markers.
The specific outcome of this dual is unknown because only corrupted footage exists, but given Imrik’s heroic deeds well onto the Second Founding, it is believed that he must have won won. It is of note that Imrik made no mention of this dual in any reports.
Iron hands
Fleeing Isstvan V, the shattered legions took whatever steps needed to get to a modicum of safety. Though most of the Avernii clan of the Iron Hands fell on the black sands, Iron-Father Luumik Yvald managed to extradite himself alongside a contingent of Ordo Pentarii before escape was rendered impossible. Instead of regrouping with the remainder of their legion and walking into Tybalt Marr’s trap, the warp spat Ordo Pentarii out in Xyphos.

Centurion Sjargan Vanjoidh had taken command due to Luumik’s nascent psychic powers being unleashed on Isstvan V and being deemed unfit for command. Whilst the Iron Hands looked on psychic arts with suspicion at the best of times, the fact that Luumik’s powers manifested spirits of those dead on Isstvan V greatly unsettled his fellow legionaries.
Sjargan refused to submit to Octavian’s authority under the Supreme Headquarters Loyalist Forces Xyphos. Instead Sjargan took the Iron Hands to pursue their own agenda of killing traitors wherever possible, in particular on the 22nd Millennial of the Emperor’s Children.
This cohort of Ordo Pentarii were last seen defending the world of Sanewor alongside a banner from House Makvar in 014.M31.
Whilst most Astartes forces that fought in Xyphos belonged to a specific legion, there were some other units that defy such categorisation and instead appear to be outcasts on their own missions. Little known in the wider Imperium, though scholars have taken to calling these units ‘Blackshields‘. It is impossible to know how many of these Blackshield units fought in Xyphos, but this author has managed to piece together information on two groups to be able to chronicle with any confidence.
The Noosemen
A unit calling themselves The Noosemen first identified themselves on Jemerq’ua. They arrived in a light cruiser that orbital stacks flagged as the Dragon Claw, recorded as lost on Isstvan V. However most traces of this ship’s former life in the Salamanders legion had been scoured clean. Each marine’s armour was painted black and they had no discernible markings.

After massacring the Imperial Army defence force stationed there, raiding the munitions complex and publicly hanging the entire royal family from the main spire, the marines simply left. Their only legacy was a brutal civil war and the following vox broadcast:
Betrayed by one father, abandoned by another. We are masters of our own fate.
Adore us. Loathe us. It matters not.All that matters is you kneel.
Vox broadcast stemming from the main hive on Jemerq’ua.
Numbering only 34 marines, the Noosemen would continue to cause havoc in Xyphos despite their size, attacking both Traitor and Loyalist forces alike. The focus of their attacks seem to have been two-fold: (1) executing planetary governors and other leadership figures; and (2) press-ganging arms, armour and recruits.
Their fate post Heresy is unknown to this author despite months in the Alexandrian archives.
The Unresolved
This group appears to have gained its name after an Administratum official labelled the first pict recording of these marines as “Unresolved Astartes“. Subsequent appearances indicate a force of some three hundred marines, with limited armoured support.
Although each marine had an aquila stamped on their forehead, it is difficult to class these as a truly loyalist asset as they have refused any communication through both Supreme Headquarters Loyalist Forces Xyphos and civilian channels. It should be assumed that any allegiance to the loyalist cause was nominal at best.

What primary sources this author was able to find report them as ‘monstrous and savage fighters’ who, once they joined the battle, tear apart everyone in front of them. Perhaps disturbingly, we have had reports of the Unresolved feasting on corpses after a firefight, but this has not been corroborated by an pict recording and so this author dismisses this as hyperbole.






























































