Event · M33
Sixth Founding
The Sixth Founding is one of the numbered Foundings that raised new Space Marine Chapters under the Codex Astartes in the centuries after the Horus Heresy. It belongs to the same institutional lineage as the First Founding, which produced the original Space Marine Legions, and the Second Founding, in which Roboute Guilliman’s reorganisation broke the surviving loyalist Legions into smaller Chapters. Conducted under the authority of the Adeptus Terra from Terra itself, the Sixth Founding drew on gene-seed stocks preserved from First Founding Chapters to establish further Chapters loyal to the Imperium, extending a programme of military expansion that continued for millennia after the Heresy. The Founding is recorded as part of the broader effort to rebuild and garrison the Imperium during the era of the Scouring, when reclaimed and contested sectors required standing Astartes garrisons beyond those inherited from the original Legions. New Chapters raised in the Sixth Founding were assembled and trained according to the Codex Astartes discipline that Guilliman had codified, receiving their gene-seed, colours, and charges from the Administratum’s founding tribunals before deployment to their designated recruiting worlds. Accounts differ on precisely which Chapters trace their origin to this Founding rather than to its neighbours in the sequence, as Departmento Munitorum records from the period are fragmentary and some Chapter chronicles favour later, more flattering traditions of their own origin. As with the other numbered Foundings, the Sixth Founding’s chief legacy lies in the Chapters it added to the Adeptus Astartes’ order of battle, some of which are held to have served into the present era while others passed from Imperial record through destruction or disgrace. The event is significant chiefly as a link connecting the twenty Legions of the Great Crusade to the many hundreds of Chapters recognised by the Adeptus Terra today, each tracing its gene-seed through a specific Founding back to one of the primogenitor Legions. Within the Orrery’s timeline, the Sixth Founding sits alongside the other post-Heresy Foundings as a marker of the Imperium’s long institutional effort, administered from Terra, to sustain its Astartes strength across the millennia.
See where Sixth Founding occurred on the galactic map in the 41st Millennium.