The Slann are the intelligent, amphibious or reptilian alien race who were the primary bioengineered servants of the Old Ones, a mysterious alien species or possibly a group of distinct intelligent species who may have been the first intelligent beings in the Milky Way Galaxy. They played a pivotal role in the history of many of the current intelligent races of the galaxy, including the Eldar, Jokaero, Humans, Orks and Necrons.
The Old Slann
The original first edition of Warhammer 40,000 called Rogue Trader explained that the Slann actually were the Old Ones. These original Slann are known as the Old Slann, and were an ancient and advanced race, the greatest of all the spacefaring races. They guided the development of the Eldar to become the inheritors of their achievements. It is suggested Eldar and Mankind share a common ancestor. There is little physical difference between Eldar and humans, and it is said the two races are genetically close enough that it is possible for them to interbreed.
The Slann's history differs from most archetypal super-advanced civilizations which reach a golden age and then suffer a cataclysm which all but destroys their race. It is said no records exist of any destructive cataclysm befalling the Slann. At some point, the Slann simply retired from their role in galactic affairs, perhaps coming upon some great cosmic truth.
The Old Slann had developed the original Webway, which was later extended and perfected by the Eldar when they inherited the Slann's role in the galaxy. As well as teaching the Eldar about the many positive aspects of the Warp and the psychic abilities it could confer, the Old Slann are said to have forewarned the Eldar about the dangers that they would face from their own natures. When the Fall of the Eldar came long after the time of the Old Slann, those few that had heeded the warnings survived.
The Jokaero and the Orks are also suggested as being the possible creations of the Slann.
The Old Slann's descendants survive into the current Age of the Imperium as the Slann, resembling humanoid frogs with a Mayan/Aztec-like culture that itself may be indicative of their ancestors interactions with primitive humans on Terra. Although no longer concerned with galactic affairs and existing in a much more primal state, most Slann colonies maintain their advanced technology and knowledge.
The Old Ones
The Old Ones of the Warhammer 40,000 universe's history are possibly an ancient race of nearly immortal, cold-blooded reptilian creatures, who were probably the first race in the galaxy to have evolved sentience (it should be noted that the C'tan predate the Old Ones, but the C'tan did not partake in the affairs of the galaxy until the Necrontyr gave them physical bodies just before the start of the War in Heaven). A supposedly benevolent and gentle race, they appear to have wished to nurture the younger races and protect them from the C'tan. It is possible that the Old Ones are the same Old Ones that the Lizardmen worship in Warhammer Fantasy, as in the Lizardmen army book it states that the Old Ones came from other worlds and found the Warhammer World, then proceeded to terraform it and create intelligent races like the Elves and Dwarfs to live upon it. They were inherently patient as a race, and before attempting to step out into the galaxy they made an extensive study of astronomy and nature, which led them to discover the Immaterium. At the time, the Immaterium was unaffected by the psychic emissions of other intelligent races since they did not yet exist, and so it was a calm and steady realm. The Old Ones were able to exploit the Immaterium to construct a great network of portals and gateways, allowing them to travel across the galaxy at a whim.
On their travels, the Old Ones seeded many worlds with life, and encouraged the development of indigenous life on many more. Terra is believed to have been seeded in this way, with the Old Ones bringing primitive life to the world. Other sources state that the human race and other species on Terra evolved without the intervention of the Old Ones.
It should be noted that the Old Ones in the Warhammer 40,000 universe may be connected to the Old Ones in the H.P. Lovecraft mythos. The term often applied to the Great Old Ones or the Elder Things which created life on Earth (Terra) in the H.P. Lovecraft mythos. But this is merely conjecture and has not been definitively stated as fact.
The War in Heaven
One of the few groups of living beings the Old Ones encountered millions of Terran years ago that were already sentient were the Necrontyr. Where the Old Ones were long-lived, with an average lifespan of many millennia, and had access to Warp gate technology that allowed them to travel from world to world instantaneously, the Necrontyr were short-lived, and were bound to only a single, highly inhospitable world that suffered from constant highly radioactive solar flares that vastly shortened the Necrontyr lifespan. The Necrontyr grew increasingly jealous of the Old Ones once they learned of their existence, and set about going to war with them. The Old Ones easily out-maneuvered these early strikes by making use of their Webway and the Necrontyr were soon defeated.
However, the Necrontyr then discovered a C'tan living within their home star. The C'tan were intelligent beings of pure energy who existed solely in the physical universe and fed off the energy of that stars themselves. In a short time the Necrontyr managed to create the necrodermis technology that allowed the C'tan to manifest physically as matter rather than pure energy, and the Necrontyr began to view the C'tan as gods. With the help of the C'tan, the Necrontyr were able to turn the tide of their war against the Old Ones, though the C'tan exacted a high price from their Necrontyr worshippers--the Star Gods discovered that the life energies of intelligent beings were far more appetizing than the bland solar energies of the stars. In time, the C'tan tricked the Necrontyr into transferring their consciousnesses into humanoid bodies also composed of necrodermis to secure immortality, but the price of this transformation was the loss of free will and most self-awareness, so that the Necrontyr, now the souless mechanical beings called the Necrons, became the slaves of the C'tan. The Star Gods sent their legions of Necrons out into the galaxy to preform the terrible "Red Harvests" of intelligent beings upon whom the C'tan could feed.
In the great conflict that followed known as the War in Heaven, the Old Ones created and modified many new intelligent races to help them defeat the Necrontyr. The C'tan, who were beings who had no psychic ability and were creatures solely of the physical universe, had no ability to comprehend the Immaterium, and thus the Old Ones came to the conclusion that they would create a series of races attuned to the Warp, in order to use the vast repository of psychic energy present there as a potent weapon against the C'tan. Of these races, a few survive today, such as the Eldar, Jokaero, Hrud, the Krork (who, it is speculated, became the Orks) and to a certain extent humans (although humans were not specifically created by the Old Ones for this purpose and may have had the psyker gene seeded into an already naturally-existing gene-pool.)
The Enslaver Plague
The new psychically-attuned races' seething collective unconsciousness had a devastating effect upon the Immaterium: their emotional emissions bled into it, twisting the once peaceful dimension into a violent realm, fuelled by the strongest emotions, giving the Immaterium a new name, the Warp, the Realm of Chaos. The vast majority of the psychic entities that dwelled in the Immaterium became malicious and dangerous. One such group of beings, called the Enslavers, managed to discover a way to force entry into the material realm, and began to psychically enslave huge numbers of sentient beings as physical gateways thrugh which they could bring more of their kind into the physical universe to feed. This new invasion dealt a fatal blow to the Old Ones (all of whom were killed or fled the galaxy) and forced the C'tan and their Necron minions into hibernation on their Tomb Worlds, as the C'tan (who feed on the sentience of other beings) had their food supplies stolen from them. It has been hinted in recent publications that some of the Old Ones did indeed survive the War in Heaven.
In the fictional universe of Warhammer 40,000, the Slann were a reptilian or amphibian species who were servants of the Old Ones (although some sources state that they in fact are the Old Ones) not unlike the Lizardmen of Warhammer Fantasy. The Slann are reputed to have created, on behalf of the Old Ones, some of the major intelligent races in the Warhammer 40,000 universe, the most notable of which are the Orks (who refer to them as the Brainboyz) and the Eldar (who are the only race that keeps records from such an ancient time). These species were created with their potent psychic abilities to take part in the war between the Necrons and the Old Ones in which they were all but wiped out by the C'tan and the Enslaver plague. The human race of Terra, by contrast, was a naturally-evolved intelligent species for which basic evolution was allowed to continue without the guidance or interference of the Old Ones.
There were five generations of Slann spawned by the Old Ones. The Slann of the first generation have all died off, many likely killed in the war between the Old Ones and the Necrons. This outcome is very similar to the origins of the Slann as told in the mythology of Warhammer Fantasy.
- Codex Titanicus (1st Edition), pp. 52-53
- Realm of Chaos: Slaves to Darkness (1st Edition), pg. 215
- Warhammer 40,000: Rogue Trader (1st Edition), pp. 131, 194-195
- Warhammer 40,000: Rulebook (4th Edition), pg. 139