Event · M35–M36
Thirteenth Founding
The Thirteenth Founding, also called the Dark Founding, was a creation of new Space Marine Chapters authorised from Terra in the 35th and 36th Millennia. It is numbered among the successive foundings by which the Imperium drew fresh Chapters from the geneseed of the original Legions, and it followed the Second Founding of the 31st Millennium, in which the Codex Astartes had first required Chapters to be limited in size. The authority to raise such Chapters is recorded as resting with the High Lords of Terra, working through the Adeptus Terra and the Adeptus Mechanicus, while the Chapters supplying geneseed remained the ultimate source of the new stock. Of all the foundings, this one is among the most poorly documented, and accounts of its course differ. Later tradition holds that the name “Dark Founding” reflects the scarcity and secrecy of its records, and some accounts associate it with Chapters whose gene-stock or conduct was later regarded as questionable. Which Chapters belong to it, how many were raised, and which parent lines supplied their geneseed are matters on which the Imperium’s surviving records are incomplete or contradictory, and this entry does not assign specific Chapters or events beyond what is attested. Obscure Chapters such as the Golden Halos are sometimes discussed in connection with the period, but their exact place in it is uncertain. In the aftermath, the Chapters of this era are recorded as having followed uneven fortunes: some are believed to have been lost in the wars of the following millennia, while others survive on the margins of Imperial records and are monitored with caution by the Ordo Hereticus and the Inquisition. On Orrery, the Thirteenth Founding is anchored to Terra as the seat of authority that sanctioned it, and it sits on the timeline between the Second Founding and the later Chapters raised in the 41st Millennium. Readers tracing its contemporaries and consequences are best directed to the Codex Astartes, the Second Founding and the individual Chapter dossiers linked to this period.
See where Thirteenth Founding occurred on the galactic map in the 41st Millennium.