Navigators (Homo navigo) are
Warp tainted freaks three-eyed mutants that are responsible for keeping your sorry-ass ship from getting lost in the warp and stopping the evil little critters from dropping a Slaanesh Patrol onto your bridge. Well-known as arrogant cock-suckers who have families richer than Bill Gates and twice as corrupt as any third world country's government.
Navigators were created through genetic engineering during the Dark Age of Technology when humanity realized that a special kind of person could find his way through the Warp better than any piece of technology. Though warp travel is possible without Navigators it requires huge banks of cogitators to perform the necessary calculations and is limited to short jumps somewhat analogous to a sailing ship hugging the coastline rather than cutting right across the sea (although when you read the retconned fluff on Tau ships it gets more confusing, since they used to use the cogitator method). Psykers such as Librarians or Sorcerers can also fulfill the duty of guiding a vessel through the warp but they are far less reliable and not particularly sustainable when compared to perpetuating bloodlines of capable Navigators, who, with the third eye in the middle of their forehead, can look directly upon the Warp and perceive its currents, allowing longer and safer journeys through the very heart of the Warp.
Since the Astronomican didn't exist at the time before the Imperium, we can only assume the humans of the Dark Age of Technology only proceeded with very short warp jumps, or used artificial warp beacons or some sort. It is known that devices such as the Pharos existed, which acted as warp lanterns capable of illuminating worlds for safe travel, but they are considered to be non-human in origin. In any case, the combinations of Navigators and the Astronomican gave the Imperium a huge advantage in reach that would be unmatched by anything short of the Webway and facilitated the Great Crusade and the maintenance of the Imperium up to the current date.
The issue of whether Navigators are true psykers is a hazy one. Though it is blindingly obvious that they are mutants with a strong connection to the warp, they never manifest psychic potential in the same way as a traditional psyker and are not subject to the same risk of psychic phenomena or perils of the warp when attempting to manifest their abilities. It is described that Navigators use their abilities in a more intuitive and passive manner, therefore they might be considered "safe" in comparison to the cataclysmic potential of an unbound psyker since a rogue navigator has little to no risk of being possessed or accidentally summoning hordes of daemons on a bad day. However, some particular uses of their powers might lead them on a much slower path to insanity due to their connection with the warp; while some abilities (such as Immolate the Soul) skirt the boundaries of acceptability that can lead to Navigators being named witches or sorcerers regardless of the truth. In any case they are not collected by the Black Ships nor are they subject to the same sanctioning processes and restrictions that ordinary psykers are. On the flip side, technologies and techniques that affect psykers have similar sorts of effects on Navigators so the two groups overlap each other to at least some extent.
The genes that make a Navigator are recessive (which leads to some suspicion Big.E. had a hand in their creation). If a Navigator mates with a regular human, all their kids will be normal. (Just like what happened when Septimus, a normal human, had a son with Octavia, a Navigator before Variel kidnapped their child to create Decimus as Talos' successor) They thus had to form an endogamous caste by resorting to lots and lots of in-breeding, giving rise to the oft-told Imperial Navy joke, "How do you tell the difference between the Navigator's sister and father?" "You don't, they're the same person!" [sound of laughing followed by a summary execution]
However, the Navigator genome is not stable like abhumans, and thus they are mutants. While their bodies conform to the holy human form while they are younger; prolonged exposure to the Warp, coupled with unstable genetics will result in the Navigator developing mutations that deviate too far from the human form to be publicly accepted. The rate and sequence of mutation is not uniform and varies from family to family and from Navigator to Navigator. However, the mutations are cumulative, eventually resulting in something that looks like a giant frog. These members are known as the Elders, who actually form the leadership of a House. To maintain a public appearance, the Elders select the patriarch or matriarch of the House, known as either a Novator or Celestarch. In the earlier days of the Imperium, these grand poobahs used to accompany expeditions and were so talented they could guide fleets through the most tempestuous warp storm. Nowadays they're too precious to waste on anything dangerous, save for inter family murder-bickering on Terra or as a last resort.
When the Emperor set about uniting Terra and preparing to go to the stars, he was presented with a bit of a dilemma: Part of the Imperial Truth that he was spouting maintained that "Humans" (ie: not mutants) were destined to rule the stars, unfortunately he was still centuries away from getting the Webway project up and running. Simply put, the Emperor needed the Navigators, even if he was fully aware of how "age before beauty" was a horrible lie to the Navigators.
Deciding "fuck it, we need space travel", the Big.E. went to the Paternova (the leader of the Navis Nobilite) and made an agreement: "Keep to yourselves in your part of Terra and your mutant Elders out of sight, and we'll pay you to fly our starships and protect you from some of the more zealous anti-mutant groups". The Paternova agreed, and thus humans can fly through the Warp, using the Astronomican to navigate.
It is strongly hinted that the Emperor planned to do away with the Navigators following the completion of the Webway project. While some Navigators were involved in the development of the technologies that the Emperor would later use, the greater knowledge of the plan was kept from the Navis Nobilite for fear of how they would react with the loss of their monopoly on space travel and potential obsolescence. Indeed, during the Horus Heresy the Navigators considered the mere prototypes of the Webway project to be such a threat that they were prepared to sacrifice a loyalist legion in order to destroy the technology.
In the 41st millennium, the Navigators are part of the High Lords of Terra, represented by the Paternoval Envoy. A lot of people in the Administratum, the Ecclesiarchy, and the Inquisition aren't too thrilled with this, but they can't really do anything to the Navigators without irreparably crippling the Imperium. The more extreme ones still try to do something about it. Imperial dogma is frequently contradictory. Pointing this out is
Bloodlines & Houses
Despite the running joke (and reality) that all Navigators are fantastically interbred, the are not a completely homogeneous group. The distinction between bloodlines is a very important factor in determining their abilities, specialties, and how they actually navigate the warp itself.
Some families exhibit higher rates of mutation, some lower. Some families are invariably mad, while some exhibit unusual warp related powers beyond the others, some can only navigate the warp after performing bizarre rituals that might involve human sacrifice or imbibing noxious compounds. The sheer diversity between Navigator bloodlines and houses is immense, with new strains branching off from time to time to form new families.
Despite defying neat categorisation, there are roughly four groups of Navigator House.
- Magisterial Houses: Those who might be considered "purest" in that they have either selectively cultivated or reduced rates of mutation. They might be able to draw their lineage back to the original Navigator families from before the Imperium and are most likely to have holdings on Terra and hold the respect and awe of other noble houses.
- Nomadic Houses: Families who have taken to space borne life like travelling gypsies. They are easily the most proficient of Navigators, but may equally be considered the most bizarre and unrelatable.
- Shrouded Houses: Also known as Beggar Houses, who for some reason or another have fallen on hard times though it might only take a change in fortunes for a house to change its status back to eminence. They might still have limited holdings, but cannot count on the wealth of support that being a Navigator normally offers so they tend to have some of the most "people skills" and almost universally have an enhanced warp sight born out of self reliance that allows them to sense warp disturbances.
- Renegade Houses: Those houses that have been officially cut off from the Navis Nobilite for some reason or another. Technically that does not make them renegades or traitors to the Imperium, though all traitor houses are Renegade Houses by default. It does mean that they are most likely to exhibit mutation due either due to self tampering or by being disconnected from official breeding programs. As with Shrouded Houses, it is possible for a Renegade House to be brought back into the fold due to careful politics, following the certain prohibitions or performing the correct penances.
Being exposed to the malign influence of the warp as part of their day job, coupled with the fact that they mutate at the drop of the hat; the Inquisition (about the only people who can really touch them) keeps a close eye on the Navigator Families and has destroyed more than a few who became corrupted. The Navigators try to resolve such problems internally, knowing how overboard the Inquisition likes to go. Wars between Navigator Houses are not uncommon, but are frequently done on the down low. It is a mutually agreed-upon rule that you can wipe a rival House out and no one bats a third eye, but so much as leak one photograph of their Elders and pretty much every single Navigator in the Imperium will turn on the transgressor ASAP. From birth the Navigators are told just how fragile the whole charade about their mutation into a frog-fish hybrid is and it's very much drilled into them not to tell anyone about their visit to Granny in the basement.
The Paternova & Heirs Apparent
As mentioned earlier, head honcho of the Navis Nobilite is the Paternova. Not only are they probably the most grotesquely mutated example of their kind (pictures of the Paternova have never been released) they are able to exert some kind of influence over the entire subspecies of Navigator, and are therefore the reason that bloodlines and lineage are so important to the Navis Nobilite.
When the Paternova kicks the bucket, every thousand years or so, give or take, every Navigator in existence will feel the effect, and create a period of anarchy where their powers function inconsistently. Each House will have someone called an Heir Apparent within their ranks, usually the oldest or most powerful of their number, but not always and they can come from any tier in their society. These Heirs Apparent are affected differently and instead of facing a reduction in powers will start to hulk out, becoming larger and stronger with their natural powers becoming more pronounced.
The Heirs are instinctively drawn into combat with one another to fight in GLORIOUS MACHO COMBAT, only gaining more and more powers and adaptations with each fallen contender until the inevitable Highlander moment when there is only one remaining to claim the prize. In this case the "prize" is the immediate restoration of all Navigator powers everywhere and the enhancement of the abilities of the family that they belong to; most likely bringing with them a considerable increase in prestige and reputation until their own Paternova croaks it.
Because of his importance, the Paternova is said to be the guiding father (or mother) whose powers transcends the Warp itself. Whether or not this is true, the sheer influence that the Paternova holds over the entire species of Navigators regardless of their position in the galaxy potentially either makes them one of the most significant psychic individuals short of the Emperor himself, or it could be a natural reaction for all Navigators towards having a stable heirarchy, the phenomenon is not well known and has hardly been explored in the fluff. Such is the importance placed on the Heirs Apparent that they treat each other as bitter rivals, and constantly plot to eliminate each other even when the Paternova still lives and breathes, something that perpetuates the ongoing rivalry between the houses. All so that they can increase their chances of claiming the top job if the Paternova drops dead during their lifetimes.
At one end of the scale you have the heavily mutated Heirs and Paternova that are seldom ever seen by the public at large, but on the other you have the Navis Scions who represent the exact opposite. The Scions are the youngest and least mutated of the households, whose purpose is to present the public face and represent the family in their dealings with Imperial clients.
While most Navigators are sequestered aboard ships or kept within the family estates, the Navis Scions are often the only Navigators a person with little void experience will ever encounter, therefore Scions are never appointed frivolously. They are chosen from youth or even during the later stages of pregnancy to ensure that the scions do not bear any hint of deformity... or that any apparent mutation might be a calculated benefit, like appearing unnaturally beautiful or elegant. This gives rise to the illusion that Navigators aren't actually mutated freak shows, and serves to get their non-Navigator counterparts to drop their guards and keep some of the heat off when the rumours start flying.
Scions are carefully groomed in the arts of conversation and protocol and do well in a variety of roles; often finding themselves in influential advisory positions to Admirals, Rogue Traders or even just members of the Imperial Nobility. As mentioned previously, Navigators aren't "true" psykers and don't learn any of the psychic disciplines, though that does not stop some enterprising Scions from touting their skills as "psychic advisors" knowing that most uneducated folks can't tell the difference.
Eventually though, as the Navigator ages, their mutations are likely to accumulate to a point that they can no longer fulfill their position. Some Scions extend their tenures by resorting to reconstructive surgeries or cybernetic augmentation so that their deformities are removed or compensated for. Unfortunately unstable genetics catches up to most Scions eventually, where they are quietly shuffled into other duties. Hopefully by that point they will have accumulated enough wealth and prestige so that they can either retire comfortably, or lean on the connections and influence that they have gained to give themselves more advantages in the future.
There are those within the Navis Nobilite (at least within the Calixis Sector and its neighboring regions) who believe that the Navigator gene is key to the future of mankind and that they are the Emperor's Chosen guides. Certainly space travel would be impossible without them, and of all the various human offshoots or factions of humanity, only Navigators can truly claim an understanding of the perils of the Warp, having seen it first hand. The philosophy grew out of House Typhon after its Novator delved into forbidden lore and came to the conclusion that psykers were a dangerous detour from the true course of human evolution. This belief spread to other Navigator Houses to form a faction that transcended the politics of individual houses.
In particular, the Elutrian Confederacy view psykers as a threat to the future that they believe Navigators are supposed to represent. If there was ever a case to be made that Navigators were not psykers then this would be it: Psykers course and surge with the power of the warp, which Navigators cannot master but can see for themselves. Though the outlook of any particular Elutrian Devotee can vary from Navigator to Navigator, at best they see psykers as fools who would attempt to master the ineffable; at worst they see them as catastrophes waiting to happen.
The Elutrians have developed special techniques to allow them to deal with the threat of psykers and are able to turn those who wield the power of the warp against themselves, burning them out and inhibiting their use of psychic powers for a short while. These powers even work on denizens of the warp, and the Elutrian masters were said to be able to turn a Daemon with a mere glance, which was taken as proof of the purity of the Elutrian doctrine. The most fanatical of their number use these powers against psykers -whether Sanctioned or not- as a means to further their objectives.
Sufficed to say the Inquisition was not particularly happy about that notion of Navigators stepping out of their station, or engaging in self-appointed "Witch Hunts", and has them on their hit lists. The official stance from the Paternova is one of condemnation and House Typhon was declared renegade; but the Elutrian doctrines remain scattered throughout the Navis Nobilite.