Editing Siege of Terra (section)

==The Solar War==

Dorn began fortifying [[Terra]] immediately after getting word of the Heresy, knowing that it would always be Horus's eventual goal. Despite being removed from the [[Thramas Crusade|larger]] [[Battle of Phall|battles]] of the Heresy, the [[Solar System]] was touched by the conflict, with Mars erupting into [[Dark Mechanicus|open rebellion]] and numerous [[Alpha Legion|sleeper agents and cults]] trying to destabilise the Throneworld. Despite all of this, Dorn managed to do the best he could, turning Terra into the most heavily fortified system in the Imperium. He even managed to blunt part of the traitor advance at the Beta-Garmon cluster before getting ready for the final rumble they had known was coming.
[[File:Dorn-hh.jpg|300px|right]]
Terra was unique in that it had two artificial Mandeville points inside the Solar system itself, created during the [[Dark Age of Technology]]. Dorn fortified the likely approaches from the outer edge of the system and built up huge defenses around the two internal jump points. The traitors, however, were busy too: infiltrators and covert operatives sabotaged loyalist assets across the system. The [[Iron Warriors]] were the first Astartes into the breach, breaking the [[Warp]] on the First of Primus, 014.M31, using huge up-armoured [[Space Hulk|Space Hulks]] as fireships to wear down the defenses before sending their main fleet through to engage the combined Fists and Scars fleets. The inner system conflict went on for a bit, with the loyalists managing to hold out enough to slow down the advance at least for a little while.

However, under Magnus's direction, the traitors turned the Shrine of Unity comet into a vast Warp gate that allowed Horus, Angron, and Fulgrim's fleets to jump right past most of the rings of defense Dorn had come up with. On the ''[[Phalanx]]'', Dorn was preoccupied with a daemon incursion and could do little to stop the huge fleets that were now mobbing for Terra. The Martian traitors, free from the blockade that had hemmed them in for years, joined up with Horus. The Solar War had barely lasted a month, far far less than the loyalists had hoped for. The rest of the loyalist fleets, knowing they could never hope to fight even a fraction of the vast traitor armada, regrouped on the edge of the system, along with the ''Phalanx'', waiting for the moment they could make an effective strike against Horus. There were early plans for the Emperor to be evacuated to the ''Phalanx'' and escape Terra, but these were made by people unaware of what Big-E was [[Webway|doing in the basement of the palace]].