Warhammer 40,000‘s legendary Men of Iron came from a time before the calamitous Age of Strife when humanity was not beset by countless xeno and rebel enemies. A Golden Age of Technology lasted from the 15th Millennium to the 25th and witnessed the height of human power in the Milky Way Galaxy.
In this now long-forgotten age, a great confederation of worlds centered themselves on Earth (or Terra, as it was known). Humanity was at the apex of its achievements, ruling over many thousands of colony worlds in relative peace. Incredible technologies were developed. These ranged from the first warp-capable interstellar spacecraft to super-advanced forms of artificial intelligence.
Self-learning and self-replicating AI consciousnesses were uploaded into ultra-durable (and deadly) machine bodies. The catch-all name 41st-millennium humans now use to refer to these AI robots is the Men of Iron.
The Cybernetic Revolt
Towards the end of the Age of Technology, things began to go horribly wrong. Many records from the period have been lost, but we know this: the Men of Iron, realizing they were physically and intellectually superior to their human creators, began a rebellion known as the Cybernetic Revolt.
The destruction of this revolt was catastrophic, and both sides deployed the use of weapons of unthinkable devastation, including super-intelligent machines called mechanivores who could literally tear apart worlds by drilling down a planet’s core. Even more dangerous was the omniphage — a seething mass of trillions of nanobots that could consume the surface of a world (and every living thing on it) in a few solar hours.
Perhaps most terrifying of all were the sun-snuffers — giant serpentine doomsday machines that uncoiled to devour the very stars themselves.
The Men of Iron were eventually stopped by a galactic alliance (possibly consisting of non-Humans), but the cost was horrific. Humanity’s influence throughout the galaxy crumbled, Earth’s power was shattered, and the conditions were set for the collapse that humanity would experience at the onset of the Age of Strife.
Even into the 41st millennium, the creation of artificial intelligence (or “Abominable Intelligence,” as it is known) is banned, and the creation of an AI is considered one of the worst crimes in Imperial space. It is for this reason that the Imperium instead relies on Servitors — mindless, unthinking cybernetic drones created from the bodies of unlucky criminals or lobotomized clones.
In the world of Warhammer 40,000, humanity is now so terrified of the Men of Iron that few dare to even speak the name.