Changes

During the [[Age of Strife]], Mars endured long centuries of isolation as complete anarchy ripped through [[Terra]].{{Fn|6a}} During the long time Mars was cut off from Terra by [[Warp storms]]{{Fn|7}}, Mars's own atmospheric shields gave way, exposing it to deadly radiation that devastated the planet. During this time, fallout shelters represented the only hope for one's survival on Mars. Technology, now responsible for one's very existence, soon became revered and the worship of the [[Omnissiah]] began in earnest.{{Fn|6a}} Any humans remaining outside the shelters devolved into cannibal mutants or were wiped out by insane automata and A.I. which stalked the surface.{{Fn|9b6b}}

Long before the Terran [[Unification Wars]], the survivors on Mars had developed their own culture, guided by the [[Cult Mechanicus]]. They eventually reunited the planet, founding the Mechanicum. As time went on, Mars began to send expeditions to Earth to reclaim lost technology there, and even sent fleets into the void beyond the Sol System to found new Forge Worlds.{{Fn|9b6b}} Eventually, the [[Emperor]] would unite Terra, and established [[Treaty of Olympus|a union]] with Mars, bringing the red planet back into the fold.{{Fn|2}} During the [[Great Crusade]], the [[Titan Legion]]s of Mars marched alongside the newly created [[Space Marine]]s.{{Fn|2}} However, during the [[Horus Heresy]] Mars became a key battleground as the loyalist Mechanicus and [[Dark Mechanicus]] split. In the resulting [[Schism of Mars]], which devastated the planet, the Dark Mechanicum eventually emerged victorious.{{Fn|4}} After the traitors took over Mars, the [[Imperial Fists]] blockaded the world for several years as the Heresy waged, only to be "liberated" by Horus' traitor forces during the final stage of the [[Solar War]].{{Fn|12}} Mars was again claimed by the Imperium after [[Horus]] was defeated in the [[Battle of Terra]].{{Fn|5}}