 The Great Crusade was a uniquely human endeavor that combined the efforts of almost numberless billion. While the Astartes are indeed the most famous and now infamous soldiers of humanity to rise out of those long lost Halcyon days, they were eclipsed in sheer numbers by the incredible bulk of the Exertus Imperialis, or Imperial Army, the baseline humans who made up the vast majority of the Imperium's military might during that period. The regiments that encompassed the incredible scale of the Exertus were as diverse as our species, ranging from barbarian tribespeople to penal battalions to entirely mechanized forces to professional soldiery with millennia-long traditions. And the roles all were suitable for, ranged as far and wide as their compositions did. But in the same way the Astartes could not be everywhere, the army could not always accomplish strategic aims as well as might be necessary. There was a gulf, a middle ground, if you will, between Astartes and Auxiliary. It was into this breach, and countless others, that the subjects of this entry were to confidently stride. Know then that this is a record of the elite, the most disciplined, the most indefatigable formation of baseline humanity in the Great Crusade. The Solar Auxilia. As the name doubtless indicates, the Solar Auxilia were formed within the Sol system during the earliest days of the Great Crusade at the behest of the Emperor and the War Council. The burgeoning Legionnaires Astartes were, while an often highly effective fighting force, still far too few in number, for the sheer demands the Great Crusade was to place upon Imperial manpower. The galaxy is almost incalculably vast, and even what star charts the Imperium possessed at that time were hopelessly out of date. None who lived in those days, even the Master of Mankind himself, knew of the sheer amount of lost human worlds, nor pernicious Xenos races the Crusade would encounter, but all knew that the Astartes were not nearly enough in number to cover the military burdens the expanding Imperial volume would require. This necessity gave birth to the Imperial army, but the additional need for specialist formations within the Great bulk of the Exertus gave birth to the Solar Auxilia. They were, in a very real sense, a purposefully created division. The remit was, in its own way, simple. A front line force of professional soldiery was required to fight alongside the legions, but also independently in both void and hostile environment operations. The Solar Reclamation had demonstrated first hand the direct necessity of having such a formation to call upon. Mercury, Venus, Ceres, Ganymede, Uranus, Pluto, Sedna, all hard fought battlegrounds upon which the Legion as Astartes secured victory thanks to their gen-hanced physiques and Mark II patterned power armor. The unaugmented humans who fought by their side faced considerable challenges, and unsurprisingly considerable casualties in the unforgiving and lethal environments of the home system. Fortunately for humanity and its great endeavour, the Sol system had an answer to this need. As Terra had descended into the millennia of warfare and genocide that marked the age of strife, a loose alliance of petty kingdoms, asteroid enclaves, lunar colonies, and orbital arcologies formed a united league in the near space of Saturn, in the spirit of necessity more than any grand ideology. Internessine strife was common amongst these polities, as vendettas and feuds easily sprang up during the millennia of privation, enforced upon radically different cultures in close proximity to one another, but despite this they nonetheless banded together in the defence of their planetary volume, to stand against the depredations of Xenos slavers and mutant pirates, who sought to exploit the precious resources of population and minerals Saturnine space could claim. The Saturnine Ordo, as the military became known, was long before Terran Unification, the most powerful fleet-based armed force in the Sol system, and their highly trained and experienced troops were experts in void structure and hazardous environment engagements. Indeed, many a student of Imperial history can point to just how instrumental the Ordo and its military infrastructure was in the formation of the first extra solar expeditionary fleets, as well as the addition of many ancient vessels under its command to the legions, the Mechanicum and the Exertus Imperialis. Upon joining the Imperium, the Ordo had additionally in effect formed the first of the Solar Auxilia. Ten regiments of the Saturnine Rams were included in the complement reports of the first expeditionary fleets, which, upon examination, were simply the Ordo's void hoplates, identically equipped, identically structured, now bearing the standard of the Crusade, along with the ram sigil of their old Ordo. While the military achievements of these rebranded hoplates were many, perhaps the truest value of the Ordo lay in their pattern itself. Following upon the heels of the first ten Saturnine regiments were yet more musterings. This time utilizing what suitable, genetically stable populations remained upon Terra and Luna and amongst the recently liberated and compliant Mercury, Venus and Jovian moons. The Mechanicum, ever eager to subsume what technological secrets the Sol system retained, almost leafily fast-tracked the research and development of the Saturnine pattern weapons and arms that the polities and the Ordo had preserved for millennia, including the specialized void armor of the hoplates, that was to serve as the signature appearance of the solar auxilia for the entire course of the Great Crusade and the following Horus heresy. Owing to the hazards inherent in combat upon the moons of Saturn's volume, the panoply of the auxilia had been designed to provide the maximum amount of protection to baseline unaugmented humans. This, combined with the regimental restructuring of the War Council, designed to ensure maximum tactical flexibility, ensured that the solar auxilia pattern could be rapidly and successfully exported to potentially any recruitment populace. This became rapidly necessary, as the Emperor and the War Council had predicted, once the solar reclamation was complete and the Great Crusade left the home system. The adaptability of the formation's pattern allowed potentially any world within the newly expanded Imperium to raise such regiments, and, indeed, many were, with command and training operations granted to veterans of the Rams, but still remarkably junior officers and non-commissioned officers from other regiments. Owing to the auxilia's void clearance and hazard specialities, they were exclusively held as a fleet-based formation, allowing the Imperium's policy of severing regimental ties to a home world to be enacted with even greater ease than amongst other formations in the Imperial Army. Preference for recruitment was initially shown for cultures or worlds with naval traditions, or ones in possession of numerous in-system colonies, in order to minimize the amount of training necessary for the solar pattern. But as the Crusade expanded further, and aptitude testing and disciplinary procedures advanced in tandem, the Exertus efficaciously applied the solar pattern to regiments raised from worlds in proto-industrial, feudal, or even feral levels of technological sophistication, in some cases, with great success. Regiments such as the Chthonian headhunters, seconded to the expeditionary fleet of Horus lupercal, and the Caractal scarborn, combined the savagery of their technologically regressed barbarian cultures with the sheer discipline and firepower of the solar auxilia to become truly fearsome combatants. Two centuries in to the Great Crusade, approximately 20-25% of all unaugmented humans in the Imperial Army belonged to the regiments of the solar auxilia, which by rough estimates would put their numbers in the tens of millions at the very least, considering the almost unaccountable size of the army as a whole. The sheer success of the solar pattern lay in both its adaptability, but also in the results it obtained, with separation from their home symptoms affected early in the regiments' history, and the recruits indoctrinated into a pattern of life and into a culture developed half a galaxy away. Chances of rebellion were next to nil, for those soldiers had no longer any ties, cultural, familial, or otherwise, to whatever old regime was extant on their homeworld. With the Astartes perennially leading the Imperiums vanguard, the bulk of the auxilia, around two-thirds, was generally stationed within the Imperiums' borders to root out possible sedition, serve as professional garrisons for systems either critical to Crusade operations or deemed at risk of Xenos predations, or simply as a fleet-based, highly-trained task force to be rapidly deployed to meet a military need when regular army regiments could not be counted upon and the Legion as Astartes were light years away. The remaining third were assigned to the expanding front lines, or to roving rogue-trader militant flotillas operating far beyond the Imperiums' borders. In the case of the former, the tight discipline and efficacious solar auxilia formed the core of numerous smaller-scale expeditionary fleets when Astartes' elements could not be provided to them, or when the Astartes' presence was not as substantial as in others. In general, these regiments would be under the command of a Lord Marshal, directly appointed to the position by the War Council, and thus in possession of an incredibly formidable amount of administrative and military authority for an unaugmented human, one who possessed the power to appoint his subordinates to gubernatorial positions on newly compliant worlds, or issue letters of mark to fleet captains, granting them the status of rogue-trader. Owing to the latter especially, the rogue-traders of the Imperium valued the solar auxilia highly as a perfect military force to accompany their flotillas, as, aside from the 20th Legion, no Astartes could consider such a position worthy of their time and attention, and regular army formations could not be counted upon to provide combatants suited to the void warfare or hazardous environments that rogue-traders would often encounter. With both this governorship over a new colony world as potential prizes of service, the solar auxilia cohorts destined for frontline and frontier operations became highly sought after postings for the more ambitious of the Imperial Army's officer cadre, and beyond. While the Exertus Imperialis was at its core a meritocracy, this did not stop the insidious tentacles of Imperial politics from embedding themselves into its bureaucracy. Ruthless officers from other regiments jostled with scions of noble houses from across the Imperium for positions, eager for the plunder and personal wealth such a role could potentially offer. It may affront the examiners of this record to be presented with this, but it is a sad reality that, as much as the spirit of human unity and our manifest destiny amongst the stars was the impetus for many to join the crusade, so too was the allure of coin and the desire for power. This being said, the very nature of the solar auxilia's role and the theatres in which they fought would rather efficiently make corpses of those whose desires outweighed their capabilities. The rewards of service were not simply for the officer class, too. Many Imperial Army regiments, beyond the most ruthless, offered some form of compensation once tours of duty were complete. There was no standard, for there was no standard of anything in the Imperial Army, but this, generally speaking, came in the form of a pension and a plot of land upon a newly founded colony world. The solar auxilia, this was the mandatory minimum, and both the size of the plot and the world upon which it was located, were far more generous than those given to other Exertus regiments. A standard tour in the auxilia was 30 years, but the reward would increase incrementally with each tour served, as the finest unaugmented soldiery within the Imperium's borders were granted access to Juvent and anti-aging treatments beyond the reach of common regiments. They were very regularly utilized, as owing to the rapid disconnection each had from their homeworld, life in the auxilia often became an all-consuming thing, all that they had really ever known and all that they were likely to ever want. The solar auxilia represents perhaps the most successful pattern of baseline human soldiery ever developed outside of the Cadian pattern, utilized by the modern Astra Militarum, and in many ways, the auxilia were far better equipped and trained than their Imperial Guard successors. Please allow for the next record upon the arm's armaments and tactics of the solar pattern to be sifted from this data stack for your perusal. Until such a time, Ave Imperator, Gloria, and Excelsis Terra. Description and on the channel page.