"The blasphemy of the Tyranids is such that only one solution is acceptable. Extermination. There can only be two sides in a fight - choose carefully, lest you and I find ourselves on different sides."
— Chaplain Ortan Cassius, Master of Sanctity of the Ultramarines Chapter
Cassius vs. Tyranids

Chaplain Ortan Cassius on Styxia Prime, marshaling his Ultramarines Chapter against the monstrous Tyranids

Ortan Cassius, also known as "The True Believer," is the senior Chaplain and Master of Sanctity of the Ultramarines Chapter of Space Marines. He is also the currently oldest active member of the Ultramarines Chapter not contained within the armoured chassis of a Dreadnought. What little of his skin can be seen amid his life-sustaining bionics is gnarled and battle-scarred, and his one good eye burns with unfulfilled vengeance. Though Cassius is many Terran centuries old, his arm remains strong and his aim true.

His impassioned words have carried the Ultramarines into battle on thousands of worlds, firing his Battle-Brothers with his own deeply-held passion and belief. Though Cassius is close to 400 standard years old, his sturdy presence on the Ultramarines' line of battle still fills the hearts of his younger brethren with pride and valour.

Ortan Cassius is a warrior of impressive presence, even for a scion of Ultramar. His gaze is as cold as the void -- it is said he could stare down a pack of Donorian Clawed Fiends with the intensity of his contempt – though in battle the fires of his fury are hot enough to inspire all who hear his stentorian tones. Cassius was put forward as an exemplar of Imperial values by the Lord Macragge himself, and rightly so. Since his induction into the Deathwatch, his inspirational hatred of the xenos has galvanised every operative he has spoken to. In Mankind’s eternal crusade, such indomitable conviction is the greatest weapon of all.

A survivor of the First Tyrannic War, Chaplain Cassius fought alongside the Ultramarines Chapter Master Marneus Calgar against the monstrous Tyranids of Hive Fleet Behemoth. He barely survived the failed rescue attempt of the doomed 1st Company at the polar fortress of Macragge during that great conflict. Cassius was laid low by a rampaging Carnifex, and managed to sustain himself only through the application of his formidable will until such time that the Chapter's Apothecaries could tend his ruined body. He is now kept alive by extensive bionic enhancements and what little organic skin that remains on his body is gnarled and battle-scarred. His one remaining biological eye burns with unfulfilled vengeance against the Great Devourer.


Deathwatch Service

Deathwatch Cassius

Deathwatch Chaplain Ortan Cassius during his Long Vigil.

Chaplain Cassius is exceptional even amongst the ranks of the Ultramarines. After learning many horrible truths about the nature of the xenos menace during his tenure in the Deathwatch, he was discharged with full honours. The Chaplain returned to the Ultramarines Chapter, bringing back the secrets he had uncovered over the course of his Long Vigil.

It was Ortan Cassius that led an Aquila Kill-team to Ghosar Quintus after the suspicious disappearance of Inquisitor Chaegryn, uncovering the Genestealer Cult that festered beneath the Mining World's surface. Since that fell discovery he has made it a personal crusade to prove the spirituality of Mankind superior to the perversion of religion that erupts before a Tyranid invasion.

Chaplain Ortan Cassius Updated

Chaplain Ortan Cassius of the Ultramarines Chapter

1st Co. Veteran Terminator

Doomed Veterans of the Ultramarines' elite 1st Company sell their lives dearly during the Battle of Macragge

In 745.M41 Hive Fleet Behemoth made the Tyranids' first contact with humanity when its massive swarms assaulted the Eastern Fringe of the Imperium of Mankind, and made rapid progress towards the heavily populated Realm of Ultramar. This conflict would come to be known as the First Tyrannic War. Upon learning of the threat posed by the monstrous xenos, the Ultramarines' Chapter Master Marneus Calgar (always "young Calgar" to Cassius) drew up plans to defend his Chapter's realm. Deeming Macragge as the star system most vulnerable to the Tyranid menace, Calgar ordered the already formidable defences of Macragge to be further improved.

Calgar declared that the Hive Fleet would be halted at Macragge before it consumed more of Ultramar or drove deeper into the heart of the Imperium. Only scant weeks later, the outrider vessels of the Tyranid Hive Fleet attacked the Ultramarines' homeworld and unleashed the infamous Battle of Macragge. The Hive Fleet was defeated after the Emperor-class Battleship Dominus Astra intentionally detonated its Warp-Drive, creating a Warp vortex that destroyed the majority of the Hive Fleet. Calgar's surviving starships then came about and roared back to Macragge to try to save the Chapter's beleaguered polar garrisons.

Chaplain Cassius led the attempt to rescue the doomed 1st Company at the northern polar fortress of Macragge. Few of Cassius' companions emerged unscathed from the terrible close quarters fighting. Only at a great cost in life did the Ultramarines hunt down the Tyranid invaders and exterminate them, though their victory proved pyrrhic at best. Cassius himself was laid low by a rampaging Carnifex, his life sustained only by his own formidable strength of will.

After a long convalescence, the Chapter's Apothecaries rebuilt the Chaplain's shattered body with extensive cybernetics, eventually enabling Cassius to return to his duties. Filled with new fire and purpose, the ancient Chaplain felt that he had been blessed with a revelation as he lay dying. He came to believe that the Tyranids assault represented a rightful punishment for Mankind's lack of vigilance, and in Cassius' eyes there was no greater calling than to purge the vile xenos from the galaxy.

Tyrannic War Veterans

Tyranid War Veteran

An Ultramarines Tyrannic War Veteran

In the aftermath of the Battle of Macragge, the Ultramarines were faced with the herculean task of rebuilding their most experienced body of Veteran warriors -- the 1st Company. Responsibility for this undertaking fell to Chaplain Cassius, whose hatred for the Tyranids and all they had done to the worlds of Mankind knew no bounds. Cassius petitioned Marneus Calgar for the authorisation to raise a new body of Ultramarines drawn from the ranks of those Astartes who had survived the First Tyrannic War. Only those Space Marines who had been tested like he had, could truly understand the threat posed by the Tyranids.

Calgar eventually acceded to the grizzled Chaplain's request. With the Chapter Master's sanction given, the Chaplain gathered his corps of Tyrannic War Veterans. Under Cassius' leadership, those Battle-Brothers who had fought the hardest against the Tyranid swarms that had assaulted Macragge were elevated and afforded additional duties, until each was eventually judged worthy of joining the ranks of the slowly reconstituted 1st Company.

Initially few in number, each new clash by the Ultramarines with the Tyranid Hive Fleets provides new Astartes for the cause. Cassius' followers have become an ever more influential faction within the ranks of the Ultramarines Chapter. Though a minor deviation from the Codex Astartes, Marneus Calgar, the Lord Macragge, tolerates his mentor's divergence from its sacred tenets, sensing that someday there shall be another reckoning between the Ultramarines and the Tyranids, and that Cassius' Tyrannic War Veterans may be the key to final victory.

Cassius has had other run-ins with the Tyranids and their allied creatures in recent years. At some time in the late 41st Millennium, Cassius lead his fellow Battle-Brothers in a series of desperate battles to purge the Genestealer Cult from the world of Torhaven. Later, Cassius fought with other elements of the Ultramarines Chapter on the planet of Kolovan against the Tyranids of Hive Fleet Kraken. There he killed the Swarmlord that was later reincarnated on the Tyranid Hive Ship, made even more deadly by the memories of its experience fighting Cassius that were restored by the Hive Mind.


Chaplain Cassius Battle

Ortan Cassius, Master of Sanctity, arrayed in his fearsome panoply of war

Chaplain Cassius is arrayed in the standard panoply of a Space Marine Chaplain, which includes:

  • Artificer Armour
  • Skull Helm - One of the most iconic elements of a Chaplain's wargear is his macabre Skull Helm, a stern visage that depicts the face of the Emperor mordant, evoking the Emperor's wrath. These helmets may take many different forms and have been crafted by numerous Space Marine Artificers across the galaxy. Universally, however, they are all fearsome in aspect.
  • Crozius Arcanum - Shaped in the form of either a staff or a mace topped by the double-headed Aquila of the Imperium or a winged skull that represents the Emperor's sacrifice, the Crozius Arcanum serves as both a melee weapon and the primary badge of office of Space Marine Chaplains.
  • Rosarius - Another symbol of a Chaplain's office, the Rosarius takes the form of a gorget, amulet, or signet ring of adamantium usually shaped into the form of the Imperial Aquila or a Gothic Cross with a jewel in the centre, and houses a powerful protective Conversion Field emitter, protecting the Space Marine Chaplain from attacks both physical and psychic that might otherwise break through the protection of even the mighty Space Marine Power Armour or the indomitable psychic strength of a Chaplain's own will.
  • Infernus - Infernus is a master-crafted Combi-Flamer crafted and sanctified by Cassius himself. Infernus' Bolter is loaded with specialised Hellfire bolts whose warheads are filled with a powerful mutagenic acid. Since the First Tyrannic War, every one of these rounds has been painstakingly inscribed by Cassius with the name of an Ultramarines Battle-Brother slain by the Tyranids.
  • Terminator Honours (Crux Terminatus) - This is one of the most famous of all Space Marine icons. Only the honoured 1st Company Veterans of a Space Marine Chapter fight in suits of Terminator Armour and wear this badge. The symbol has various forms and designs but all versions are carved from great chunks of stone with a large skull in the center of it, to signify the rank and authority of the Veterans who have earned the right to wear it.
  • Crusader Seals - Crusader Seals are waxen or metallic tokens with vows of piety and Chapter blessings inscribed on hanging strips of parchment that are bestowed upon Space Marines of proven zeal and courage.
  • Frag Grenades
  • Krak Grenades


  • Cassius (Novel) by Ben Counter, Chs. 1,4,9
  • Codex Adeptus Astartes - Space Marines (8th Edition), pp. 97, 133
  • Codex Adeptus Astartes - Deathwatch (8th Edition), pg. 32
  • Codex: Space Marines (7th Edition) (Digital Edition), "The Chronicle of Heroes - The Torhaven Incident"
  • Codex: Space Marines (6th Edition), pg. 108
  • Codex: Space Marines (5th Edition), pg. 87
  • Codex: Ultramarines (2nd Edition), pg. 73
  • Deathwatch: First Founding (RPG), pp. 69-70
  • White Dwarf 305 (UK), "Purge the Alien - Ultramarines Tyrannic War Veterans" by Graham McNeill, pp. 84-89
  • White Dwarf 266 (UK), "Index Astartes: For the Emperor (Space Marine Chaplains)," by Anthony Reynolds
  • White Dwarf Weekly 109 (27 Feb 2016), "Ortan Cassius," pg. 30
  • Catechism of Hate (Novella) by Gav Thorpe


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