Event · M31

Imperium Secundus

Imperium Secundus was a short-lived second Imperial state proclaimed at Macragge in 009.M31, after Ultramar lost contact with Terra. It was formed by the primarch (one of the Emperor’s gene-forged sons) Roboute Guilliman, and briefly ruled jointly with his brothers Lion El’Jonson and Sanguinius, on the reasoning that if the Emperor’s realm had fallen to the Warmaster Horus, a new seat of order was needed to preserve Imperial civilisation. Macragge, secure and well-governed under Guilliman, was judged the safest foundation for such a state, and at its height the polity encompassed the Five Hundred Worlds of Ultramar. The crisis that produced it followed the Battle of Calth, where the Word Bearers Legion under Erebus turned upon the Ultramarines during the Shadow Crusade and, through a dark ritual, summoned the Ruinstorm, a warp storm of exceptional scale that severed astropathic and navigational contact across the eastern galaxy. With the Astronomican’s guidance lost to the region, Guilliman turned to the Pharos, an ancient xenos beacon on the world of Sotha, whose activation by the loyalist Warsmith Barabas Dantioch allowed scattered loyalist forces to find their way through the storm to Macragge. Guilliman, already consolidating the Five Hundred Worlds in the aftermath of Calth, was joined there by Lion El’Jonson and the Dark Angels, by Sanguinius and the Blood Angels in the wake of the Signus Prime campaign, and by remnants of several other Legions, with no word of the Emperor’s fate reaching any of them. Reluctant to crown himself Emperor and risk the self-aggrandisement he condemned in Horus, Guilliman proposed a regency to hold the eastern Imperium together. Sanguinius, judged the least ambitious and most trusted of the three primarchs present, was named Imperator Regis, an Emperor-in-waiting, a role he accepted with evident reluctance, while Guilliman took the title Lord Warden and Lion El’Jonson became Lord Protector. A significant test of the new order came at the Battle of Sotha, where loyalist forces defended the Pharos against attack, securing the passage that sustained Imperium Secundus. Konrad Curze reached Macragge hidden aboard the Dark Angels flagship Invincible Reason, on which he had evaded capture for some sixteen weeks after the Thramas Crusade, and descended in a commandeered drop pod during a mass landing he had triggered from within the ship. He rampaged through the capital, killed Phratus Auguston in a chapel of the Fortress of Hera and, holding off Guilliman and the Lion together, detonated explosives he had rigged about the chapel; the two primarchs survived only because Barabas Dantioch drew them to Sotha through the Pharos. Curze later penetrated the throne room of Imperium Secundus, wounded Azkaellon and held him hostage, and told Sanguinius that he had foreseen both their deaths; when Sanguinius refused his invitation to strike him down and urged him to seek redemption, Curze set off a further trap and escaped. Accounts differ on the shape of his opposition to the regency: one presents him as openly contemptuous of the enterprise and doubtful that Terra had fallen, while another records him working with bandits hostile to Guilliman and sending a suicide bomber against a strategically important bridge in the capital. Unrest attributed to Curze led Lion El’Jonson to place Macragge under martial law, deploying the Dark Angels’ Dreadwing against the worst-affected regions, until the Lion cornered him in the Alma Mons region, broke his back over his knee rather than kill him, and brought him before Sanguinius for trial. There Curze admitted his deeds but denied that they were crimes and set Guilliman and the Lion against each other with accusations of secret orbital strikes; he was spared execution when the Lion, citing Curze’s foreseen death at an assassin’s hand as proof that the Emperor lived, knelt and swore to be his gaoler. Accounts differ on how fully Imperium Secundus was ever formalised before events overtook it. Visions received by Sanguinius, together with testimony wrung from the captive Curze, eventually persuaded the triumvirate that the Emperor and Terra endured, and by 014.M31 the rationale for a second throne had collapsed. Guilliman abandoned the coronation, and Imperium Secundus was folded back into the Realm of Ultramar, its governance passing to a regency under Valentus Dolor; he, Sanguinius, and Lion El’Jonson then led their Legions back through the Ruinstorm to rejoin the war against Horus, though only Sanguinius and the Blood Angels reached Terra before its end. Because it was conceived in a moment of despair and dissolved once proven unnecessary, Imperium Secundus was afterwards downplayed in Imperial record-keeping and is said to have been counted by Guilliman among his own gravest errors. It nonetheless marks a significant convergence of Guilliman, Sanguinius, and Lion El’Jonson at Macragge during the Horus Heresy, and a moment when the Five Hundred Worlds stood ready to serve as the Imperium’s last redoubt had Terra truly fallen. Vulkan, primarch of the Salamanders, was also on Macragge during this period. One account records that, after months of captivity under Konrad Curze following the Drop Site Massacre, he escaped by activating a teleporter in his hammer Dawnbringer and fell into Macragge’s upper atmosphere, where his body burned on re-entry. The Ultramarines recovered the charred remains, which regenerated over several days into a living but mentally broken primarch. Sensing Curze on the planet after the Night Haunter escaped from the Dark Angels flagship Invincible Reason, Vulkan broke his bonds, armed himself from Guilliman’s armoury and fought Curze across a city, learning to hasten his own regeneration by force of will. The duel ended when John Grammaticus, a Perpetual sent by the Cabal to deliver the Fulgurite, a petrified bolt of the Emperor’s psychic power, to Curze, used it himself at Eldrad Ulthran’s urging and stabbed Vulkan through the heart, at the cost of his own perpetual nature. Another account records that the comatose body of Vulkan was brought to Imperium Secundus, where scattered Salamanders under Zytos also gathered. Guilliman, Lion El’Jonson and Sanguinius placed Vulkan’s body in a stasis capsule made by Guilliman and inscribed Unbound Flame, and the surviving Salamanders on Macragge stood guard over it.

See where Imperium Secundus occurred on the galactic map during the Horus Heresy.

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