"Offer the incantation of activation, speak forth the litany of retribution and deliver unto the enemy the wrath of the Omnissiah."

— Brother Barabel, Praetors of Orpheus Techmarine

The Praetors of Orpheus is a Loyalist Space Marines Chapter and a Second Founding or "Primogenitor" Successor Chapter of the Ultramarines. The Praetors of Orpheus' understanding of Imperial science and technology is second only to that of the Tech-priests of the Adeptus Mechanicus itself.

Many believe that the two organisations are tied by more than shared service in the Emperor's name and that the Praetors have shared personnel and goals with the Mechanicus in the past.

The large number of Praetors of Orpheus who undergo cybernetic augmentation with bionics would lend weight to this theory. The Praetors of Orpheus are currently active in the star systems neighbouring Pavonis.

Chapter History

PoO Marine

Praetors of Orpheus Chapter Colour Scheme as displayed by a Firstborn Space Marine.

The Praetors of Orpheus is a Second Founding Successor Chapter of the Ultramarines and is therefore considered one of their honoured Primogenitors. The Praetors maintain their fortress-monastery on the world of Orpheus Prime, within a vast subterranean complex called the Labyrinthe of Orphia. This Chapter is famous for its disciplined approach to the Codex Astartes.


Praetors of Orpheus Chapter Colour Scheme as displayed by a Primaris Marine; the Praetors of Orpheus display their company colour and numeral on their left knee.

This occasionally causes the Chapter to offend its allies, but also means that, on the battlefield, the Praetors operate like a perfectly calibrated engine of war. With the resurrection of their Primarch Roboute Guilliman in 999.M41 and his recent revisions to the Codex, these changes have been rapidly adapted by the Chapter, whose inflexible adherence to the word of law continues unabated.

Notable Campaigns

  • Jotun Repression (932.M39) - The Praetors of Orpheus Chapter formed Task Force Naasirka and led the assault against the army of turncoat Imperial Guard general Lord Kazanlak. Only at the last was the true cause of Kazanlak's rebellion uncovered, an edoparasitical xenos life form spawned within his skull which was controlling his actions and slowly consuming his soul. When the truth was revealed, Kazanlak's army turned upon their traitorous master and were later granted a pardon by the Space Marines strike force commander.
  • War of Beasts (Unknown Date.M42) - The Praetors of Orpheus sent two companies to the defence of the Hyperia Hivesprawl on the Sentinel World of Vigilus.

Chapter Beliefs

The Praetors of Orpheus are famous for their highly disciplined approach for executing the prescriptions of the Codex Astartes that is, if anything, too inflexible. The Codex is their guide in all things, but the Chapter's Battle-Brothers are prone to interpreting passages from the tome in too literal a way.

Chapter Relics

  • Orphean Key - An Orphean Key is a specialised combi-tool used exclusively by the Praetors of Orpheus Chapter. The tech-lore of the Praetors of Orpheus is justly renowned, both for secrets shared with the Machine Cult and knowledge unique to the Chapter. The creation of Orphean Keys is one secret the Chapter has kept to itself, granting the advanced tools only to the most senior Techmarines of their Chapter. This combi-tool can also serve as an Auspex and multi-key, functioning as a normal example of such tools. Its most impressive function, however, is the advanced Cogitator package which allows the tool to analyse unknown or malfunctioning technology and to offer a potential solution that the user of the tool can then effect.

Notable Praetors of Orpheus

  • Techmarine Barabel - A Techmarine of the Praetors of Orpheus.
  • Venerable Brother Numine - Numine is a Castraferrum Pattern Dreadnought of the Praetors of Orpheus.

Chapter Appearance

Chapter Colours

The Praetors of Orpheus wear predominantly white Power Armour. The Aquila or Imperialis on the chest guard, as well as the power pack, shoulder plate trim and bolter casings are sky blue.

The sky blue squad specialty symbol on the right shoulder guard designates operational specialty -- battleline, close support, fire support, Veteran or command.

A High Gothic numeral, indicating squad number, is stenciled in the centre of it.

Company designation is denoted by the colour of the left knee plate in accordance to the dictates of the Codex Astartes -- i.e. White (1st Company), Yellow (2nd Company), Red (3rd Company), Green (4th Company), etc.

A white High Gothic numeral is stenciled upon the left knee plate, identifying the company number. Sometimes campaign badges are indicated on a Battle-Brother's greaves.

Chapter Badge

The Praetors of Orpheus' Chapter badge is a sky blue shield with a yellow sunburst in the centre, with the exception of the top left quarter which is white with a sky blue version of the Ultramarines icon, an upside down Greek letter Omega. This shield is centred on a field of white.

Canon Conflict

Imperial Armour Volume Two - Space Marines and Forces of the Inquisition states that the Praetors of Orpheus' Chapter Homeworld is Beta Entebes II. In later publications, this is no longer considered canon, as a more recent galactic map of Space Marine homeworlds published in the Codex: Space Marines (6th Edition) shows the Praetors of Orpheus' Chapter homeworld as Orpheus Prime.


  • Codex Adeptus Astartes - Space Marines (8th Edition), pg. 31
  • Codex: Space Marines (8th Edition) (Revised Codex), pg. 27
  • Codex: Space Marines (7th Edition) (Digital Edition), pg. 114
  • Codex: Space Marines (6th Edition), pp. 8, 33, 77
  • Codex: Space Marines (5th Edition), pg. 25
  • Codex: Space Marines (3rd Edition), pg. 47
  • Deathwatch - Honour the Chapter (RPG), pg. 130
  • How to Paint Space Marines (2004)
  • Imperial Armour Volume Two - Space Marines and Forces of the Inquisition, pp. 9, 138, 177
  • Imperial Armour Volume Two, Second Edition - War Machines of the Adeptus Astartes, pg. 19
  • Strategy Card "Special Ammunition - Minor Stratagem," Planetary Empires game
  • Imperium Nihilus: Vigilus Defiant (8th Edition), pg. 79


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