Ultima Founding - History: In the latter years of the 41st Millennium, the scattered Space Marine Chapters of the galaxy have been bled dry by ten thousand standard years of constant battle. With the advent of gigantic Warp Storms that swallow whole star systems, the formation of the Great Rift and constant attacks by the forces of Chaos, rampaging xenos and more, the Adeptus Astartes are stretched thinner than ever.With many Chapter planets now actively under siege, some Chapters are confirmed as destroyed or lost, and even those faring relatively well have suffered high casualties and are in desperate need of reinforcement.With the resurrection of the Primarch Roboute Guilliman, the Avenging Son has assumed command as lord commander of the Imperium over all of Humanity's military forces. Finally, after ten millennia, he has put into action his ultimate contingency plan -- the Primaris Space Marines.These new warriors are the next step in the evolution of the Emperor's original Angels of Death, genetically altered from their brethren to be bigger, stronger and faster. The Primaris Space Marines represent timely reinforcements for the Imperium's armies as their enemies close in for the kill.This initial wave of Primaris Space Marines emerged from over 10,000 standard years of stasis fully psychologically indoctrinated to each fulfil a single strategic role. Some were Intercessors, some Aggressors and so forth, and almost all specialised only in that one area of combat.These warriors were able to immediately take up their front-line combat duties with the expertise of veterans, and all possessed a modicum of additional skill with Machine Spirits thanks to their Martian heritage.Yet ultimately they were somewhat strategically inflexible, for they had not undergone the gruelling progression through their existing Chapters' companies or gained the wealth of experience that progress bestowed. Some of these Martian Primaris Marines formed entirely new Chapters such as the Rift Stalkers or the Silver Templars.The rest joined the Indomitus Crusade as "Greyshields," fighting together with the scions of other Chapters and Primarchs as part of the force known as the Unnumbered Sons until the Indomitus Crusade fleets reached their adoptive homeworld or the fleet of the Firstborn Chapters they were destined to join.Each time such a momentous occasion came, another cadre of Battle-Brothers would peel off and reinforce the Chapter whose colours they wore and whose genetic heritage they shared. Not all of these Primaris reinforcements had an easy time integrating with their erstwhile Firstborn brothers, but ultimately all brought fresh strength to the Space Marine Chapters fighting furiously against the tide of horrors vomited from the Great Rift.The newly reinstated Lord Commander of the Imperium has decreed that those Chapters most devastated by the ongoing wars should be amongst the first to be reinforced with this new breed of transhuman warrior. Starting with the Ultramarines, but also deploying these new Space Marines to every other Chapter in need, Guilliman aims to reinforce the Imperium's scattered defenders across the galaxy. It is not just as reinforcements to existing Chapters though.Guilliman has also ordered the creation of a host of new Chapters, the so-called "Ultima Founding," composed entirely of Primaris Space Marines. The warriors of these new Chapters were created entirely using the new processes discovered by Archmagos Belisarius Cawl and established with all the necessary weapons, armour and equipment that they will need to conduct their defence of the Imperium.These Chapters still trace their genetic lineage back to the gene-seed of the First Founding, and scions of all nine Loyalist Space Marine Legions emerged from the vaults beneath the Red Planet. They benefit from three additional gene-seed organs and larger size, but it still remains to be seen if Cawl was able to successfully stabilise any of the known genetic deviations or impart any additional resistance to the effects of Chaos.Many of these new Chapters have been assigned homeworlds on the edge of the Great Rift, the Imperium's new frontline in the war against Chaos, though some have inherited the empty fortress-monasteries of Chapters that had been lost to the attrition of constant war. Many of these worlds face a continuous battle against the daemons of the Warp, as well as an unpredictable mix of xenos raiders, pirates and invaders.