The Macharian Crusade was the greatest Imperial expansion since the Great Crusade itself, a lightning campaign of conquest led by the brilliant Lord Commander Solar Macharius. In the space of only seven years, his armies swept across a vast swathe of the galaxy, bringing more than a thousand worlds under Imperial rule and earning their commander comparison to the Emperor's own generals of legend.
Macharius drove his forces with relentless speed and audacity, and the soldiers of the Imperial Guard followed him with near-fanatical devotion. World after world fell before his advance, whether won by battle or awed into submission by the sheer momentum of his crusade. For a brief, dazzling span it seemed the age of expansion had returned and the galaxy might once more be united under the Imperial aquila.
Yet the crusade ended not in defeat but in exhaustion and reluctance. When Macharius reached the edge of the explored galaxy, his weary armies refused to cross into the unknown void beyond, and the great advance faltered. Macharius died soon after, and without his singular will to bind them, his conquests fractured as ambitious generals turned on one another in a devastating civil war. The territories he had won so swiftly were plunged into the strife of the Macharian Heresy, a bitter coda to one of history's most glorious campaigns. See also the Macharian Crusade.