Changes

Later, aboard the ''Iron Blood'' off [[Mars]], Perturabo watches the data coming in regard to the final actions of the Siege of Terra. He violently rages at being denied what should have been his greatest triumph, destroying whatever can be found around him with ''[[Forgebreaker]]''. Now hating both sides equally, Perturabo contemplated killing Horus once he (in his mind by that point) inevitably prevails. Perturabo realized he will need further power to survive in a sea of enemies, and begins to wonder how to evolve himself into something far deadlier.{{Fn|20}}

By the time of Horus' death and the flight of his armies from Terra in the face of [[Roboute Guilliman]]'s relief force, Perturabo was still aboard the ''Iron Blood'' at the edges of the [[Sol System]]. He observed the [[Word Bearers]] constructing a Warp-based device on [[Neptune]]'s moon of [[Laomedeia]] in order to rekindle the power of Chaos in the System and restart the war.{{Fn|26a}} However the Iron Warrior [[Ortag Theokon]] summoned Perturabo to Laomedeia with a signal, leading to him crushing the Word Bearers, mocking their plan, and stripping the moon of all its resources and personnel before withdrawing. Perturabo indicated that he did not intend to run forever, and that he had a greater plan in mind.{{Fn|26b}}

Rogal Dorn expected an honourable battle, but this was not to be. Beginning by isolating the four Companies of the Imperial Fists from their orbital support, Perturabo began to carefully divide his enemy and destroy them piecemeal. Some Imperial Fists managed to penetrate the defences and reach the centre of the Eternal Fortress, only to find there was no central keep – simply an open space watched by yet more defenses. The fortress was a decoy of no real value, surrounded by twenty miles of killing ground. By the sixth day of the siege, Imperial Fists Space Marines were fighting individually, without support, using the bodies of their own battle brothers for cover.{{Fn|1a}}

The siege of the Eternal Fortress (later referred to as the "[[Iron Cage]] Incident") lasted for a further three weeks. Relief came in the form of Roboute Guilliman and the Ultramarines, who drove off the Iron Warriors, but the siege left Rogal Dorn a broken man and rendered the Imperial Fists Chapter unable to fight for nineteen years. The gene-seed of over 400 Imperial Fists was sacrificed to the Dark Gods, and Perturabo was elevated to the rank of [[Daemon Prince]] of [[Chaos Undivided]] {{Fn|1a}}.

Perturabo has collaborated with [[Vashtorr the Arkifane]] on many nightmarish technological projects. As such, he provided a complement of Iron Warriors to Vashtorr to assault [[The Rock]] during the [[Arks of Omen Campaign]].{{Fn|19}}

==Wargear==

**{{Endn|26a}}: Chapter 36

**{{Endn|26b}}: Chapter 39

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{{Primarchs}}