Indomitus Crusade

The Indomitus Crusade was a massive military campaign launched by the resurrected Primarch Roboute Guilliman in the aftermath of the Great Rift's opening, which tore the galaxy in two and plunged the Imperium into its darkest hour since the Horus Heresy. Beginning in 999.M41 and lasting over a century, this crusade sought to stabilize the Imperium, reclaim lost worlds, and push back the forces of Chaos.

At its heart was the introduction of Primaris Space Marines — new, enhanced warriors created by Archmagos Belisarius Cawl over ten millennia of secret work. These reinforcements, along with new weapons and vehicles like the Redemptor Dreadnought, were distributed to Chapters across the galaxy, dramatically bolstering the Imperium's military strength.

The Crusade was divided into multiple fleet groups, each carrying Primaris reinforcements to beleaguered Chapters and war zones. Guilliman himself led the primary fleet, the Crusade Indomitable, personally liberating hundreds of worlds. The Crusade officially concluded with the formation of the Unnumbered Sons into new Chapters, though the wars it sparked continue across the galaxy.