Macragge's Honour was the Gloriana-class flagship of Roboute Guilliman, master of the Ultramarines and the most numerous and ordered of all the Legions. Like its Primarch, the ship was a study in discipline and foresight, every system arranged with the same methodical brilliance that made Guilliman the Imperium's foremost strategist and administrator. It was a war-fortress governed by reason.
The vessel served as the mobile capital of Guilliman's expanding domain in the region that would come to be called Ultramar. From its command deck the Primarch directed not only campaigns of conquest but the governance of five hundred worlds, marrying the arts of war and statecraft as no other of his brothers could. Its halls saw councils that shaped the fate of the eastern galaxy.
When the Heresy erupted and treachery struck at Calth, Macragge's Honour became a rallying point for the loyalist cause. Guilliman gathered his shattered Legion and planned the salvation of the Imperium from its bridge, contemplating even the grim contingency of the Imperium Secundus.
Through the long night of civil war, Macragge's Honour stood as a beacon of order against the encroaching chaos, the flagship of the son who would one day become the Imperium's Lord Commander and its last, best hope.