The War of the Beast

Some fifteen centuries after the Horus Heresy, the Imperium of Man faced a conflict that came closer to ending it than any war since the death of Sanguinius. The War of the Beast erupted in the mid-32nd Millennium when an Ork invasion of unimaginable scale burst upon a complacent Imperium, and before it was ended the greenskins would raze whole systems, extinguish proud Chapters, and cast a shadow over the throneworld itself.

An Empire Grown Complacent

In the long centuries after the Great Scouring, the Imperium had grown ossified and proud. It was ruled from Terra by the squabbling High Lords, mediocre men jealous of their privileges, while the Space Marines had long since been broken into their separate Chapters under the dictates of the Codex Astartes. No one imagined a foe that could threaten the whole edifice at once.

Yet in the dark between the stars, the Orks were gathering as they had not gathered in ten thousand years. A power was rising among them that would weld the fractious greenskins into a single overwhelming purpose, and the Imperium, blind and self-satisfied, never saw the storm until it broke.

The Beast Awakens

The invasion began in 544.M32 and unfolded on a scale that dwarfed even the great WAAAGH! the Emperor Himself had crushed at Ullanor during the Great Crusade. Entire sectors were overrun in a matter of solar months, their defenders drowned beneath a green tide that seemed to have no end and no beginning.

At the heart of the horde marched a warlord the Imperium came to call simply the Beast. In time it was learned that this was not one creature but several, a brotherhood of monstrously vast and cunning Prime-Orks, each commanding a horde like a Legion of old. Stranger still were their weapons: moon-sized Ork constructs, the dreaded Attack Moons, that could cross the void and appear in the skies of a doomed world without warning.

The Fall of the Imperial Fists

The first great catastrophe fell upon the Imperial Fists, the sons of Rogal Dorn and among the most honoured warriors in the Imperium. Drawn into battle against the greenskins, the entire Chapter was shattered and all but wiped from existence, a blow so sudden and total that it stunned the whole of the Adeptus Astartes.

Only a single Imperial Fist survived the slaughter, the warrior Koorland, who carried the grief of his exterminated brothers and the burden of vengeance. That one Chapter, thought inviolable, could be annihilated so swiftly revealed the true measure of the threat now facing mankind.

The Moon Over Terra

The war reached its most terrifying height when an Ork Attack Moon translated into orbit above Terra itself, casting its shadow across the Imperial Palace. In desperation the High Lords flung a vast, half-armed mob of ordinary citizens against it in the doomed Proletarian Crusade, a slaughter that achieved nothing but the deaths of untold thousands.

So dire was the peril that the guardians of the throneworld were roused as they had not been in an age. The golden warriors of the Adeptus Custodes and the anti-psyker Sisters of Silence, who for centuries had scarcely stirred from the Palace, took the field once more to defend the heart of the Imperium.

The Last Wall Reforged

Hope was rekindled by an ancient protocol. Koorland invoked the Last Wall, a secret compact binding the successor Chapters of the Imperial Fists to reunite in the Imperium's darkest hour. The Black Templars, Crimson Fists, Excoriators and Fists Exemplar gathered under his command, briefly reforging the strength of a Legion in defiance of the Codex that forbade it.

They were joined by a figure out of legend, the returned primarch Vulkan of the Salamanders, whose presence lent the counterstroke a demigod's might. Turning the Orks' own nature against them, the Imperium's savants devised a weapon from the null-souls of the Sisters of Silence, a psychic silence to smother the greenskin horde. With this in hand, the reunited Astartes carried the war at last to the Ork homeworld of Ullanor to sever the Beast's head.

The Beheading and the Reforged Astartes

While the Astartes fought, the rot at the Imperium's centre was purged by blood. Drakan Vangorich, Grand Master of the Officio Assassinorum, had watched the High Lords bungle the war from the beginning, and in a single night of murder known as the Beheading he had them slain, seizing power for himself before he too was eventually put down. The government of the Imperium was remade in the ashes.

Ullanor was taken and the Beast destroyed, though the price was fearsome and Koorland fell in the fighting. In the aftermath, the warrior Maximus Thane rebuilt the Imperial Fists from the ranks of the Last Wall, and the Chapters returned to their mandated separation, more certain than ever that they must never again become the Legions that had once torn the galaxy apart. The Imperium had survived, but it emerged harder, grimmer, and forever changed by the war that nearly ended it.