Mars - Notable Campaigns and Events: Mars Expands (ca. M25-M30) - Mars overcomes strife and disaster to unite beneath the Cult Mechanicus and its ruling Mechanicum government and planetary parliament. As lulls between the waves of Warp Storms during the Age of Strife allow, the fleets of Mars travel outwards, raiding for technology and establishing new colonies of Tech-priests. With a few exceptions, such travels remain limited in scope and stay within the confines of what will later become known as the Segmentum Solar.Treaty of Mars (ca. 798.M30) - The Emperor, fresh from uniting the tribes of Terra, arrives on Mars. Many of the Tech-priests of the ruling Mechanicum declare Him to be the Omnissiah, and so the Emperor forges an alliance between Terra and its old rival Mars. It is the adepts of the Cult Mechanicus that equip the Emperor's Space Marine Legions for the Great Crusade. In recognition of the fact that to achieve His galactic plans, the Emperor needs the technological and scientific aid of the Mechanicum, Mars becomes an ally to Terra rather than her subject, which is cemented by the signing of the Treaty of Olympus Mons, known as the Treaty of Mars on Terra. Of the countless worlds that the Imperium soon claims, only Forge Worlds dedicated to the Cult Mechanicus are esteemed in such a way.Great Expansion (798.M30-004.M31) - The Emperor leads the massive Great Crusade outwards from Terra, with the purpose of reuniting the hundreds of thousands of lost Human-settled worlds scattered across the galaxy. At the fore are the Space Marine Legions, supported by the growing Imperial Army. All are equipped by the manufactoria and orbital fleet yards of Mars. No less important are the Skitarii Legions, the Legio Cybernetica, the Legio Titanicus, and the Imperial Knights that join the expedition. Planet after planet is reconquered and offered the same choice -- bow before the Emperor of Terra or be destroyed. On and on the expeditionary fleets push outwards. The Tech-priests often refer to this time as the "Great Expansion," for hundreds of Forge Worlds and Knight Worlds are rediscovered during this period alone.Horus Heresy (005-014.M31) - Like all of the branches of the Imperium, the Mechanicum finds itself rife with corruption during the epic civil war known as the Horus Heresy. Many Forge Worlds and Knight Worlds turn from the Emperor. Indeed, the Fabricator-General of Mars, Kelbor-Hal himself declares his allegiance to Horus, and so begins the Schism of Mars, a bitterly-fought campaign that mirrors those taking place across the galaxy. Skitarii Legions square off against each other while Titan duels Titan. Those of the Cult Mechanicus that turn to the Chaos Gods are forever after known as the Dark Mechanicum. They are hated and feared in equal measure, for they dare to fuse Daemons with the Machine Spirits of their war engines, creating twisted things that mock the Machine God and his true laws of order and reason.Great Scouring (014-Unknown Date.M31) - Wars of recrimination follow the Horus Heresy. Led by Roboute Guilliman and the Ultramarines, the Imperial forces fight battle after battle, driving the remaining Traitor armies back until they finally flee, seeking refuge in the Eye of Terror. The Knight houses, their honour tarnished by the vile deeds of fallen Chaos Knights, are especially vehement in their pursuit of battles of vengeance. Recognising the need for systemic change, Guilliman creates the Codex Astartes, and tasks Archmagos Dominus Belisarius Cawl with a secret task that will align the fates of the newly-forged and renamed Adeptus Mechanicus and the Space Marines of the Adeptus Astartes for centuries to come.Age of Rebirth (M31-M32) - The Mechanicum of old is reforged as the Adeptus Mechanicus and the new fabricator-general of Mars is given a permanent position as a High Lord of Terra. Crippled by His wounds during the Siege of Terra, the Emperor is interred within the Golden Throne, a device so complex that only the Tech-priests of the Adeptus Mechanicus can hope to maintain its systems.Prophet of Cogs (Unknown Date.M34) - The long-time cultural rivalry between those Tech-priests who dwell in the north of Mars and those of the Martian south flares into open war. As the conflict grinds on, both sides are assailed by the feral packs of malfunctioning servitors and burnt-out war machines that still haunt the desert wastes, many dating to the Age of Strife. The war reaches a gory conclusion when the self-proclaimed Prophet of Cogs broadcasts a control-chorus that binds millions of long-abandoned machines to his cause. Appalled by the half-living cyberghouls he sets on his foes, both the Martian north and south unite to drive him from the Red Planet. Rumours persist that he still haunts the Alpha Centauri System.Moirae Schism (ca. Early M35) - During the secession of the Segmentum Pacificus in the Nova Terra Interregnum, the rebel Forge World Moirae is destroyed by retaliatory Exterminatus, but not before the Moirae Schism has split the Adeptus Mechanicus in two. The ensuing conflict draws Titan Legions and even those Space Marine Chapters affiliated with the Adeptus Mechanicus into the turmoil. The schism takes a heavy toll on the Adeptus Astartes, resulting in the destruction of dozens of companies and the excommunication of several Iron Hands clans. It takes over two millennia of desperate warfare before the Moirate doctrines are considered fully purged.Occlusiad War (550-560.M37) - The northwestern fringe of the galaxy is ravaged during the devastating Occlusiad War by the Apostles of the Blind King, rogue Tech-priests who view Humanity's existence as an affront to the Machine God. War rages for a solar decade, but the tide turns when the palace-warship of the Blind King is found hidden in a fold of Warpspace. The Blind King is slain and the Apostles overcome -- not least due to the efforts of Mars itself and the founding of the heroic Dark Hunters Chapter.War of the Golden Cog (Unknown Date.M39) - The fabricator-general of Mars claims ownership of the riches of the Fortress of the Soulless, lair of the Culexus Temple. A disastrous civil war between Mars and Terra is averted by a sniper's bullet, but the artefact known as the Golden Cog is left in Skitarii hands.The Macharian Conquests (392-399.M41) - Led by Mars, Graia and Gryphonne IV, many Forge Worlds send armies to aid the massive crusade of Lord Commander Solar Macharius, the Imperium's greatest Astra Militarum commander of all time and a recognised tactical and strategic genius on a par with the primarchs themselves. This Imperial Crusade took place on the far western edge of the galaxy within the Segmentum Pacificus, reaching as far as the border of the galaxy with intergalactic space and even reaching into the unknown regions of the Halo Zone. The furthest extent of this crusade reached just beyond the edge of the Segmentum Pacificus, where not even the blessed light of the Astronomican could penetrate the dark void.Necrons Invade Mars (998.M41) Five Necron Shroud-class Light Cruisers entered the Sol System undetected by the Titan monitoring station. A commercial system freighter detected them. System defence ships were deployed on intercepting trajectories, but any that managed to enter range were destroyed. The Defence Monitor Javelin engaged the Shroud-class Light Cruisers near Mars, but the well-shielded vessel was destroyed by the xenos. The Necron squadron was able to avoid an outer minefield and and speed past the Deimos chain of orbital weapons platforms. The Phobos line damaged one, which was then scuttled by the other Necron vessels. The remaining Shroud-class cruisers attacked the subterranean mines of Mars for unknown reasons before Starhawk bombers launched by Imperial Navy vessels located and finally destroyed them. A perdita exclusion zone, enforced by an entire Skitarii Legion, was established around the Noctis Labyrinthus following this incident.Indomitus Crusade (ca. 999.M41 - Present) - Following the destruction of Cadia, Warp storms of a magnitude not seen since the Age of Strife wrack the galaxy. Every Forge World is cut off from its Explorator fleets and, for a time, from each other. All suffer invasions and raids as emboldened xenos and Chaos forces test them, probing for weaknesses, eager to destroy the bastions of Mankind's empire. No fewer than seven Forge Worlds are destroyed altogether and several more remain missing, buried beneath fierce and impenetrable storms. The initial Blackness that blanketed the galaxy after the Great Rift was torn open finally lifts. In the aftermath of the Noctis Aeterna, many Imperial Crusades are launched. Although there were several successful campaigns, none could claim more triumphs than the Indomitus Crusade. From Terra, Roboute Guilliman mustered a coalition. In addition to Archmagos Dominus Belisarius Cawl, Mars sent many Skitarii Legions, maniples of the Legio Cybernetica and several lances of Knights from House Taranis. Over a dozen other Forge Worlds send supporting fleets as the expedition crosses the galaxy, and many Knight Worlds prove eager to join -- none more so than the vengeful House Krast. The crusade's many victories bring a glimmer of hope to the darkened Imperium. However, once the primary fleet of the crusade returns to aid Ultramar during the Plague Wars, the remaining forces splinter, the campaign losing impetus as some Mechanicus factions return to protect their own homeworlds.Adeptus Mechanicus Unleashed (Unknown Date.M42) - With the Imperium reeling from the disastrous effects of the birth of the Great Rift, Mars commands all Forge Worlds to ramp up production to unprecedented levels. They churn through raw materials and servitors as never before, and vast armadas are launched to strip entire star systems of resources. The forges must be fed at impossible rates in order to supply the endless war materiel required.Rust Fields War Begins (Unknown Date.M42) - To fuel their factories, a coalition of Forge Worlds led by Mars and Graia sends mining fleets to exploit the vast belt of asteroids known as the Rust Fields. Although its interior has never been explored, its exterior is incredibly rich in all manner of metals, minerals and promethium seas -- a tumbling horizon of asteroids that stretches across three sectors. Soon after operations are begun, however, it is discovered that Greenskin clans rule the interior of the Rust Fields. So begins a great war that draws in untold numbers of additional Imperial forces as the Adeptus Mechanicus fights to retain its foothold.Bane of the Forge Worlds (Unknown Date.M42) - Although there are many theories, none understands the reason for the Necron attacks upon Forge World territories as well as Archmagos Belisarius Cawl. Both sides are seeking deposits of the strange material from which the Cadian Pylons were fashioned, and many Adeptus Mechanicus strongholds have been erected upon sites containing this precious resource. Cawl sends his own agents -- armies of Mars and House Taranis -- across the stars in an effort to combat the growing danger, and hundreds of battles are fought as more and more Forge Worlds are drawn into the conflict to aid their beleaguered brethren. Even those Tech-priests that begin to understand the reality of the dire situation are loath to call upon their Imperial allies for fear of being branded Hereteks.