Agathean Domain - Worlds of the Agathean Domain: Agathon (Hive World) – Agathon is a spire-type Hive World, its population housed in three distinct hive cities which owe many similarities to those of Necromunda or Khur. The world is highly organised and constitutes the industrial and economic centre of the entire Agathean Domain. It is undoubtedly the capital world of the Agathean Domain, having imposed its name on the system's alliance and protecting the planets within with its military might. Its population consists both of the original, pre-Imperial inhabitants of Agathon and the descendants and survivors of the soldiers of the 60th Expeditionary Fleet who brought it into Imperial Compliance in the 30th Millennium. In particular, the fleet's officer cadre had integrated with the local noble families to such an extent that within a few generations, the lines between them had blurred. However, the further down the social ladder, the more indifference and resentment was encountered in regard to Imperial rule on Agathon. Prior to the events of the Horus Heresy, but after Ireton MaSade's retirement as Imperial Commander, Agathon was ruled by a corps of representatives called the Parliament of Electors which had been dominated by a strong Imperial faction. However, the events of Horus' rebellion would give voice to the underlying resentment of the Imperial conquest and warrant the return of Ireton MaSade as Imperial Commander to maintain loyalty. This change in regime quickly reimposed order and purged the ranks of the Parliament of Electors of its dissidents.Legatus (Mining World) – Originally organised as a penitentiary mining colony for the dissidents of Imperial rule in the aftermath of the Agathon Compliance, by the dawn of the 31st Millennium, Legatus had become the secondary world of the Agathean Domain and its most important Mining World. The landscape of Legatus is dominated by vast tundra plains still locked in the closing stages of a climatic ice age. The planet is immensely rich in high-grade metallic ores that Agathon needs to feed its macro-industry and modest orbital shipping yards. Since 940.M30, Legatus has been subjected to three significant xenos raids; twice by Ork marauders and once by heavily mutated xenos cryptids thought to originate from the extra-galactic void. This led to a sizable military mobilisation. Legatus' standing garrison of Agathean cohorts was greatly augmented and extensive ground defences were constructed. These would prove invaluable in the dark days of the Horus Heresy.NoriciumOthion (Feral World) – Othion is a Feral World of little strategic value were it not for its native Abhuman population. An excessively arid world due to its lack of cloud cover, Othion seemingly consists of limitless silica dune seas continuously exposed to the light of its yellow sun. The world is called home by a sizable population of Ogryns who have undergone severe metabolic alterations from the standard accepted Ogryn types to better accommodate the harsh climatic conditions. This however has led to a severe devolution of the already limited intellect of the Ogryns, resulting in an inherent lack of social cohesion and mental stability. Perhaps most macabre is the pronounced drive to cannibalism of these Abhumans as well as an irrational hunger, which makes them extremely dangerous for Humans. Through extensive cranial surgery and the implementation of a "kill-switch" device to terminate them when needed, these Ogryns did, however, prove a powerful addition to regional Agathean defence forces. During the Horus Heresy, Othion's Ogryn population would constitute a considerable strategic resource which would be ruthlessly exploited by the Agatheans to bolster their standing military in anticipation of a Traitor invasion; transformed into Charonites, these Ogryns could surpass both Traitor Legiones Astartes and the creations of the Dark Mechanicum in terms of brute strength. This resurgence of Charonite squads was fairly common amongst technically advanced Loyalist star systems that had been cut off from other Imperial territories.TurhalWychval - Very little is known about this savage world at the very edge of the Agathean Domain and the known galaxy. During the bleak years of the Horus Heresy, a deal was struck between Ireton MaSade and High Seneschal Valdemar Orhlacc of House Orhlacc: a new world to call home in exchange for the military might of its Knights. This alliance would bear its fruits many times over, most notoriously during the Liberation of Numinal in 009.M31.Zarnov (Industrial World) - Zarnov is an isolated industrialised world that lies to the galactic north of the Coronid Prohibition Zone. This has led the cartographers to attach Zarnov to the Coronid Reach rather than to the Grail Abyss, which features the sole known stable Warp-route leading to the planet. Not truly part of the Agathean Domain due to its peculiar location, Zarnov's battle honour nevertheless is proudly displayed on the Vexillia of the 1522nd Solar Auxilia Cohort.