Event · M41–M42
Ultima Founding
The Ultima Founding was the raising of new Primaris Space Marine Chapters under Roboute Guilliman at the close of the forty-first millennium. It is recorded as the largest expansion of the Adeptus Astartes since the Second Founding that followed the Horus Heresy. It is tied to Terra because the Imperium’s highest authority sits there, and Guilliman’s office as Lord Commander of the Imperium gave the programme its standing. Its effects are felt across the whole galaxy, and the Chapters raised under it serve wherever the Imperium is contested. The programme followed Guilliman’s return to the Imperium’s affairs, which came as the Cicatrix Maledictum tore across the galaxy. The Great Rift severed large parts of the Imperium from one another and left its Chapters overstretched and often isolated. Guilliman turned to the Primaris Space Marines, the larger and more heavily enhanced warriors developed over many centuries by Belisarius Cawl of the Adeptus Mechanicus. Their production had been held back until then. Once released, they were sent out with the Indomitus Crusade, and the Founding drew on the same stock of recruits. Accounts differ on the exact count of Chapters created, and later tradition treats the Ultima Founding as a process that continued beyond its first year rather than a single event. The Founding was a departure from the limit of roughly one thousand battle-brothers per Chapter set by Guilliman’s Codex Astartes, since the new Chapters were built from Primaris recruits and included some formed by splitting existing Chapters. Its participants were the Ultramarines and their successors, the Adeptus Mechanicus of Mars, and the officials of Terra who sanctioned it. Its aftermath is a much larger and more varied Astartes than any since the Heresy, deployed in the war for the Imperium’s survival through the Indomitus Crusade and the later Gathering Storm. On the Orrery timeline it sits alongside the Indomitus Crusade and the opening of the Cicatrix Maledictum, and its consequences are still unfolding.
See where Ultima Founding occurred on the galactic map in the 41st Millennium.