The galactic civil war which wracked the Imperium divided the entire human war machine in two. After decades of chafing under the Emperor’s edicts, many in the Mechanicum saw their opportunity for unfettered experimentation by siding with Warmaster Horus.
Most forge worlds spread across the Imperium aggressively maintained their autonomy and preferred to govern themselves with arcane quasi-feudal hierarchies – both factors which played right into Horus’ hands following his ascension to Warmaster. The Mechanicum had remained suspicious of their Imperial allies; the early wars of unification had never been forgotten, and many tech-magi suspected the Emperor would only allow their independence for as long as it was convenient.
The scales tipped when Magister-Lictanex Regulus, the Mechanicum envoy to the Warmaster, slipped inside the Martian cordon with a delegation of Horus-loyal Iron Hands. His mission was to meet with the Fabricator-General, Kelbor-Hal, and secure Mars’ allegiance to Horus before the rebellion began in earnest, promising a treasure beyond compare – the keys to a trove of forbidden knowledge known as the Vaults of Moravec, sealed by the Emperor’s own hand.
Yet even as he plundered the ancient vault of its dark secrets, whispered from within ageless data-crypts by malevolent intelligences not of the material world, his subordinates were spoiling to settle scores with those tech-magi who refused to join the rebellion. The labyrinthine power structures of the Mechanicum could not be corrupted so easily to the Warmaster’s cause, and the archmagi who resisted would need to be wiped out for Mars to fall utterly under Horus’ banner.
The first major salvo came not from the clanking war machines of traitor Taghmata, but rather a virulent plague of scrap-code unleashed when Kelbor-Hal opened the Vaults of Moravec. It spread across the Red Planet like wildfire, worming its way through every system it touched from power regulators and shield networks to thermal safeguards and life support nodes, and at once a thousand acts of sabotage were let loose upon loyalist forge fanes across the globe.
While military systems were mostly shielded long enough to disconnect them from outside interference, the cascading wave of reactor meltdowns and critical system malfunctions slaughtered millions in a cataclysmic event later known as the Death of Innocence. However, while the scrap-code wrought havoc on those deemed too loyal to the Emperor, it changed those sworn to Kelbor-Hal in a more sinister way – warping their minds into crueller, more bellicose puppets.
This is the true beginning of the Dark Mechanicum, as genius minds were unshackled from what remained of their morality and tasked with plumbing the depths of the vault’s ancient knowledge. Endless swarms of Stalkers scuttled from their forges as once-proscribed technologies were warped by the renegade magi into lethal weapons of war, and these new legions set about conquering their loyalist kin almost as soon as the scrap-code infestation had dealt its debilitating blow.
One of the first major forges to fall was the monumental Magma City, whose systems had been broadly spared thanks to a brand new noospheric defence network and who now called the Knight Households of Taranis and the Legio Tempestus to their defence. But to find out just how the battle unfolded, and play along with the final doom of Magma City in a new Escalation Campaign, you’ll need to pick up the Rise of the Dark Mechanicum expansion book for Legions Imperialis when it goes up for pre-order on Saturday.