Event · M41–M42
Battle of Luna
The Battle of Luna was fought as Roboute Guilliman’s Indomitus Crusade reached Terra after the primarch’s ten-thousand-year sleep in stasis. Luna, the fortified moon guarding the Imperial homeworld, was the last obstacle between the returning primarch and the Senatorum Imperialis, and accounts hold that its approach was contested rather than open. It thus stands as the threshold action of the Indomitus Crusade: the point at which Guilliman’s return ceased to be rumour and became a fact the Imperium had to answer. The battle’s causes lie in the Cicatrix Maledictum, the great warp rift torn open by Abaddon the Despoiler’s thirteenth Black Crusade, which plunged much of the galaxy into the Noctis Aeterna and severed Terra from countless of its subjects. Guilliman, revived from his death-like stasis by the Archmagos Dominus Belisarius Cawl, gathered the fleets of the Indomitus Crusade and made directly for the Sol System. At Luna, Imperial Navy squadrons and garrison forces are recorded as having met the crusade fleet in confusion and, in places, open hostility, whether from warp-tainted corruption, severed chains of command, or simple disbelief that a primarch could return after ten millennia. Guilliman’s own Ultramarines and the assembled Adeptus Astartes companies of the crusade bore the brunt of securing the moon before the fleet could stand down to Terran orbit. With Luna cleared, Guilliman proceeded to Terra and was received by the High Lords, who confirmed him Lord Commander of the Imperium and Imperial Regent, a title last held in substance by his father. The Indomitus Crusade launched from this footing, carrying Guilliman’s reinforcement fleets, including the newly raised Primaris Space Marines, to relieve besieged sectors across the stricken Imperium. Luna itself remains reckoned among Terra’s inner defences, and the battle is remembered less for its scale than for what it opened: the return of a primarch to a galaxy that had learned to do without one.
See where Battle of Luna occurred on the galactic map in the 41st Millennium.