Horus Heresy - Seeds of Heresy Sown: After more than 200 standard years of hard conflict by the early 31st Millennium, over two million Human-settled worlds across the Milky Way Galaxy had been reclaimed by the Emperor in the name of the Imperium of Man. Beside Him had stood the Primarch Horus, who had fought alongside the Emperor for the early part of the Great Crusade as His only rediscovered gene-son and primary military commander, glorying in the singular attentions of his father.The long wars had forged a strong bond between them, and they were truly father and son. But now the Emperor had to consolidate His newborn Imperium, and undertake the next phase of His Grand Plan. He intended to create a Webway through the Immaterium much like that used by the Aeldari that would be open to Humanity by wielding the psychic augmentation technology of the artefact from the Age of Technology known as the Golden Throne.This work required His continued presence on Terra, and so after Horus' magnificent victory in the Ullanor Crusade, against the largest horde of Orks ever encountered in the galaxy at that time, the Emperor departed and left Horus in charge of the Great Crusade with the exclusive title of "Warmaster."As Warmaster, Horus was the commanding general of all of the Imperium of Man's military forces, charged with leading the other primarchs and their Legions through the remainder of the Great Crusade.At this announcement there was much shock and outrage. Many of the other primarchs did not understand why the Emperor was leaving them to fight the enemies of Mankind alone and, worse still, why Horus should be raised as the first amongst equals. Rogal Dorn, Sanguinius and Fulgrim were pleased for their brother, the new Warmaster, while others -- such as Angron, Roboute Guilliman, Lion El'Jonson and Perturabo -- all reacted with varying degrees of disapproval.The situation only grew worse when the Emperor announced that He would be creating a civilian administrative bureaucracy known as the Council of Terra that was comprised of Imperial bureaucrats and nobles to carry out the day-to-day governmental affairs of the Imperium, replacing the direct rule of the Emperor while He was engaged in his secret Imperial Webway Project.The Council of Terra would implement and administer the new galaxy-wide tax of resources and manpower called the Imperial Tithe and other matters of day-to-day law in the Imperium of Man while the Emperor focused on bringing His Webway Project to fruition using the technology of the Golden Throne.The primarchs would be relegated to a primarily military role as the Imperium's most preeminent commanders. Many of the primarchs, including Horus, were deeply disturbed that their father would make them subject to normal men and women who had never shed blood in the establishment or expansion of the Imperium and that he would remove them from the political positions of rule to which they believed they were entitled aftyer their sacrifices.However, the Emperor had sought to create a civilian bureaucracy for the Imperium precisely because he wanted regular Human beings to learn to govern themselves once more and not become beholden to a permanent, genetically-enhanced ruling class.The Chaos Gods would ultimately use the primarchs' resentment as one of the all-too-Human weaknesses they could exploit to corrupt half their number.