Collegia Titanica - Titan Legions: Myriad were the hosts of the Mechanicum who swore their allegiance to the Great Crusade, from the bellicose Myrmidon cults to the cybernetic flesh-constructs of the Lacrymal. Mightiest of them all, however, were the god-engines of the Collegia Titanica, a singular martial class within, and simultaneously quite distinct from, the standard ranks of the Cult Mechanicus.The towering bipedal god-engines known as "Titans" have served the Tech-priests of Mars since the time referred to only as the Era of Pathogenesis in the Age of Strife. Though little date from this time survived the millennia, it is known that Titans first appeared during a great and terrible conflict fought between the besieged forces of the nascent Mechanicum and a debased caste of cabalistic heretics named the "Cy-Carnivora."Vast swathes of the blasted red wastes of Mars had fallen to the Cy-Carnivora Mekwrights and it took the creation of three entire Titan Orders of what would become the Collegia Titanica to defeat them. These three Titan Orders were collectively named the "Triad Ferrum Morgulus," and it was from the template of their creation that all future Titan Orders were founded.Created to defeat the monstrous hunger-engines of the Cy-Carnivora, little could stand before a Titan, and nothing before an entire Titan Order, which at its height might number between 200-300 towering engines of destruction. Having finally driven the horrors of Old Night from Mars, the Titan Orders were frequently fielded in the service of one forge city against another in a series of internecine civil wars and religious schisms, which seeded enmities that would bear bitter fruit in the dark times to come.When at length the Emperor came to Mars and the Treaty of Mars was sworn at the great Martian mountain of Olympus Mons, the Titan Orders were turned to the service of the Great Crusade where their devastating weaponry, impregnable armour and the peerless skill and devotion of their pilots proved every bit as destructive against recalcitrant Human empires and xenos horrors as they had against the Cy-Carnivora.As the Great Crusade expanded ever outwards from Terra, the hosts of Humanity encountered numerous Human-settled worlds. Many were possessed of only the basest technologies, while a few were the equals of Mars itself. Thus were discovered the colonies sent forth by the Mechanicum into the void during the Long March of the Age of Strife.Such was the deep-rooted imprint of the Cult Mechanicus that, even separated by long, lonely millennia and tens of thousands of light years, these autonomous machine-domains recognised and acknowledged a manner of fealty towards the Mechanicum of the Red Planet. While each of these Forge Worlds would remain sovereign, until much later at least, each swore powerful oaths to the Tech-priests of Mars in shared veneration of the Omnissiah.The greatest of the newly-discovered Forge Worlds were found to host their own Titan Orders, and while many had developed their own unique and sometimes idiosyncratic cultures, others were discovered to have organised themselves along a similar line to the original Martian Triad Ferrum Morgulus, suggesting some underlying machine principle or pattern at work, which the lords of Mars looked upon and found pleasing. Of the lesser Forge Worlds not possessed of the necessary templates, resources or expertise to construct and operate their own Titans, Mars favoured those who swore fealty with such patronage that they might do so.Within scant solar decades of the outset of the Great Crusade, the Mechanicum had discovered or founded a score of Titan Orders, and by the turn of the first century of the Great Crusade, the orders of battle by which the Titan Legios arranged themselves had become somewhat codified, and while individual bodies exercised considerable variation in strategy, a degree of standardisation was evident.The fabricator-general of Mars proclaimed that the many Titan Orders should be recognised as a distinct class within the greater corpus of the Mechanicum, that its doctrines, traditions and battle honours might be propagated and preserved for the good of all Mankind. This body was to be known as the Collegia Titanica, and while the Legios themselves would remain subservient to the will of the individual forge lords, it would soon become a politically influential entity within the emerging structures of the nascent Imperium of Man.The Collegia Titanica came to rate the strength of each Titan Legion according to a complex formula that allotted each a "militaris" grade. First tier designations ranged from primus to denarii, with a range of further clausal numerical definitions describing the Legio's specific capabilities, specialisations and other characteristics. Though it rarely told the whole truth, the most obvious measure of a Titan Legion's strength was ever the number of god-engines it could field, with the largest maintaining as many as 200-300, while the smallest might be able to muster barely a dozen.In reality however, the mixture of Titan classes was a far more reliable indicator of potency of a Legio than raw numbers. Few indeed could field the colossal Imperator-class, while almost all fielded significant numbers of Warhound Scout Titans, the lightest common god-engine, with the ubiquitous Warlord, the standard Battle Titan, a proven and powerful design which made up the bulk of most Legios' main strength. There were many other classes besides, notably the ancient Reaver and several Warlord variants such as the Nemesis and Nightgaunt and other, rarer chassis whose designs such as the Apocalypse, Carnivore and Komodo were unique.Many Titan Legions had a particular mix of god-engines they preferred to commit to battle, exemplifying their own specific battle doctrines. The Legio Audax, also known as the "Ember Wolves," for example, fielded a large number of Warhound Scout Titans, employing them as fast-moving hunting packs that were fearsomely effective at harrying and bringing down far larger enemy engines. Most Legios however, sought to maintain a balanced and flexible force able to prosecute a wide range of operations and confront many different foes.Though some Titan Legions used their own vernacular, the Collegia Titanica enforced an overall degree of standardisation in unit nomenclature. Depending on their role, Titans were fully capable of operating individually, and often did so when supporting conventional Imperial ground units.In practice, they were often deployed in formations of anything from two to ten god-engines, but broken into formal units known as a "maniple" comprising five god-engines -- the numeral 5 having an occult and numerological signifier of destruction in many numiscantic systems of prognostication favoured by the machine cult. The most senior Titan commander -- or princeps -- was appointed as the maniple's leader and this force was considered sufficient to prosecute all but the most apocalyptic of battles.By the height of the Great Crusade at the dawn of the 31st Millennium, dozens of Titan Orders marched to war in the name of the Emperor. The Collegia Titanica on Mars served as overall repository for the martial traditions and templates of the Titan Orders, though in reality each was in effect its own master. By the auspices of the Collegia Titanica, each Titan Order assumed its own title, including both High Gothic and Low Gothic monikers, icons, banners, colours and other unique elements of heraldry.