Navis Nobilite - Great Houses: Almost nothing is known of the earliest history of the Navigator houses, though some amongst the Holy Ordos of the Inquisition suspect that the ancient stasis vaults beneath the mansions of the Navigator's Quarter on Terra must contain records and artefacts rivalling those of the Inquisition in age and significance.Whatever secret histories of Mankind's darkest ages are hidden beneath those marble palaces are likely to remain obscured, for the Novators of the Great Houses are beholden to no other authority and even the most determined and relentless of Inquisitors would find it all but impossible to breach their closed society and force them to acknowledge any external law.Few organisations within the Imperium hold as much power as the Great Navigator Houses of the Navis Nobilite. Their position of control over nearly all Imperial shipping and interstellar commerce places them in a rare position of power, one that sits almost beyond the reach of both the Adeptus Administratum and even the Inquisition itself. It is a position that the Great Houses have mercilessly exploited down through the millennia and used to gather vast wealth and influence.The lesser Navigator families, on the other hand, owe fealty to the larger and more influential houses, who in turn have their own alliances. These alliances form trading cartels, which compete for lucrative contracts with other such unions.The Merchant Fleets of the Imperium must constantly deal with these powerful cartels for the services of the Navigators -- it is a strained relationship, but one which the Imperium constantly strives to keep the upper hand in. Though across the long span of years this power has risen and fallen, the influence of the Navis Nobilite has endured longer than almost all other Imperial edifices. The only aspect of the Great Houses that matches their political endurance is their constant struggle with each other.In their internecine struggles for position and favour, the houses use all manner of means to outdo their rivals, sometimes even engaging in open warfare against one another. Only the strict control of the house Novators and the carefully maintained codes of behaviour and tradition of the Navigators keep such conflicts from spiralling out of control.Whatever the details of their roots, the Navigator houses appear to have enjoyed a special status since time immemorial. They must have been an established and powerful body at the beginning of the Emperor's Great Crusade in the late 30th Millennium, which would have been impossible without their services.Were it not for the Navigators that guided each expeditionary fleet, the Great Crusade would have taken millennia to prosecute, not the scant two Terran centuries it actually took before the calamitous events of the Horus Heresy plunged the nascent Imperium into galaxy-burning civil war.It must be presumed that a number of houses fell to the insidious lies of the Warmaster Horus, for it would not have been possible for Horus to deploy his fleets with the speed and cunning he did were this not the case. Whatever the truth, the Navigator houses appear to have emerged from the Heresy with their power and reputation largely intact -- confirmation, were it needed, of their critical role in the very existence of the galaxy-spanning interstellar empire that is the Imperium.