The origins of the Navigator gene are shrouded in mystery and rumour,{{Fn|2f}}{{Fn|5}} even among Navigators themselves,{{Fn|6}} but firmly placed within the [[Dark Age of Technology]];{{Fn|2f}}{{Fn|5}} some various sources state them date their introduction to originate in [[M10]],{{Fn|7}} [[M15]],{{Fn|5}} [[M19]],{{Fn|8b}} or [[M22]],{{Fn|9}} in any case predating the re-emergence of [[psyker]]s in mankindMankind.{{Fn|5}} It is unknown whether they evolved on their own, or were manufactured by genetic engineering;{{Fn|2f}}{{Fn|10c}} even if the consensus leads pointed to the latter being the case,{{Fn|7}}{{Fn|11}} either would appear to be a response to mankind’s Mankind’s need to perfect [[Warp travel]].{{Fn|2f}} Since their appearance they began to extend their influence due to their crucial service within human society, forming noble houses that with waxing and waning times ultimately grew in wealth,{{Fn|7}} escaping the grasp of industrial and trading cartels,{{Fn|10d}} eventually establishing the Navis Nobilite well before the advent of the Imperium.{{Fn|12a}} It is of note that in M41 many held a belief that Navigator gene originated from the time just before [[the Great Crusade]] which took place between late [[M30 ]] and early [[M31]], manufactured by [[the Emperor]] himself.{{Fn|2f}} Some Ordos amongst the [[Inquisition|Holy Inquisition]] suspect that the ancient stasis vaults beneath the mansions of the [[Navigator's Quarter]] on [[Terra|Holy Terra]] contain records of the true origin of the Navigator gene.{{Fn|3e}} The aforementioned gene is easily lost through its recessive trait, and can only be saved for future generations through intermarriage, lost when bred with ordinary humans.{{Fn|7}}{{Fn|10c}}

The primary trait of a Navigator is their pineal eye, nested in a socket on their forehead.{{Fn|3a}} While it perfectly fills the sensory function as either of his normal eyes do, it is also extraordinarily able to open a miniscule [[Warp gate]] within ititself. From this stems all the Navigator’s powers. Although a state of the Navigators may open their third eye being open in a commonplace an unremarkable way of lifting its lid doesn’t cause the gate to open, confusingly the term “fully open” is applied when used to describe the latter happensstate required for its more extraordinary application. During the opening of said this gate, a Navigator is able to glimpse the Empyrean in its true state,{{Fn|2f}} although their mind converts this image to a more mundane approximation; only in with age the allegory recedes to ring closer of does this comforting illusion recede, leaving apparent the true horror of the [[Warp]].{{Fn|2b}} Nonetheless , the ability to observe the Warp is crucial in their function as navigational officers, allowing them uniquely to have some semblance of assurance of their position within it. While the eye always appears within a genetically pure newborn, in some cases it is located deep within the skull, requiring trepanning surgery and/or a cybernetic shutter for it to be brought to its proper spot. Those These surgeries commonly occur during a Navigator's adolescence.{{Fn|2f}} If, even with both of the parents being Navigators, a newborn has his Navigator gene dormant, and no Third Eye to speak of, they are called a [[Typhlotic]]. Even if the child is a barren fruit of the line, they aren't known to be harmed, and are kept around, although the specifics of their role in the house are unknown.{{Fn|13b}} Notwithstanding the Navigators' toleration of their unfortunate typhlotic kinfolk, the appearance of them within a lineage is considered a threat to the house's survival. Across the their history there were a few known houses who slowly but surely lost the ability to produce purestrain genestock, and at some point not even spending their whole fortune on [[bloodbroker]]s and unsound marriage arrangements is able to save the house from falling back into baseline humanityHumanity, without any such useful abilities as their ancestors possessed.{{Fn|3f}}

Due to unspecified reasons Navigators normally keep their Third Eye hidden, covered with a bandana or any other decorative piece.{{Fn|7}} It is noted on one occasion that a Navigator only kept her Third Eye hidden when outside the safe haven of the spaceship, freely unveiling it while stepping aboard, with the notion of doing so only speculated by her peers to come with familiarity of this environment.{{Fn|14a}} In stark contrast, Navigators of the [[Elutrian Confederacy]] proudly flaunt their third eye, more even, instead covering their mundane eyes, considering them to be of no importance to their status.{{Fn|3l}} While the most prominent of the Eye's powers is known to be extremely lethal, it is under full conscious control of the Navigator, being utterly harmless on its own without the Navigator's decision to otherwise be.{{Fn|2f}} Psychically inclined individuals however can still sense the eye even if covered, although no one but the most powerful of psykers note notes the effect,{{Fn|15}} and most baseline humans often doubt the existence of this mythical eye, until in a rare occurrence they are given a chance to see it.{{Fn|7}} It however is often met with disappointment as it ends up being an unimpressive peculiarity,{{Fn|14a}} if not a reason to brand and detest them as a mutant on the first occasion of noticing the eye.{{Fn|14c}}

Of additional mention are an increased longevity Other quirks of the Navigators, who are a superior lifespan (even without [[juvenat]] treatments one can easily live up to around three or four hundred years;){{Fn|7}} and the fact that no Navigator can be born a psyker: (although classified as psykers in some instances, they can't possess any standard psionic gift, inherently lacking any [[The Assignment|psy rating]]).{{Fn|2h}}