On the Aquila banner that embodied the Imperium's supreme majesty, the keen-eyed, double-headed eagle gazing imperiously over the Sea of Stars carried a profound and subtle symbolism.
One eagle's head represented the Imperium of Man itself, commanded by the Emperor, with Terra as its heart and the Legiones Astartes and Imperialis Militia as its talons.
The other head, held just as high and gleaming with a cold metallic sheen, pointed toward the planet suspended above red deserts, forever shrouded in the roar of gears and prayers of data—Mars, and the vast, singular Adeptus Mechanicus it represented.
Admittedly, in law and in name, the Adeptus Mechanicus was an inseparable part of the Imperium.
The two sides had concluded the sacred "Treaty of Olympus," shared an ambiguous intersection between faith in the "Machine God" and faith in the Emperor, and cooperated closely in the grand war against xenos and heretics.
In practice, however, the Adeptus Mechanicus was more like an independent kingdom allied with the Imperium and possessed of extensive autonomy than a simple administrative department within it.
It enjoyed enormous independence: its own laws, its own armed forces, its own territories, and even a complex, closed hierarchy of advancement and governance separate from the Imperium's administrative system.
Its monopoly on technology, its grip on the lifeblood of military production, and its fragments of forbidden knowledge concerning the Dark Age of Technology formed a solid foundation for its power, often giving it considerable leverage and confidence in its dealings with other Imperial factions.
The Adeptus Mechanicus could be described as a colossus standing alongside the Imperium of Man, each dependent on the other, yet each keeping the other in check.
It was now the end of the thirtieth millennium.
The golden tide of the Great Crusade was sweeping across the Galaxy, and