The Old Ones were an ancient and technologically advanced intelligent race of cold-blooded reptilian beings who established an interstellar empire across the Milky Way Galaxy tens of millions of standard years before the development of most of the other sentient species currently existing in the galaxy. They are the creators of the Eldar and many other intelligent races of the galaxy such as the Slann and the Jokaero, as well as the possible ancestors of the Orks, and are known to Mankind mainly through Eldar mythology.
The Old Ones are an ancient intelligent race of nearly immortal creatures of a slow and cold-blooded intelligence who may have been reptilian in nature. The Old Ones were probably the first species in the Milky Way Galaxy to have evolved sentience (though the C'tan, born at the creation of the galaxy, predate the Old Ones, though they did not partake in the affairs of the galaxy until the Necrontyr gave them physical bodies just before the War in Heaven). The Old Ones possessed extremely advanced technology and potent psychic powers that made them essentially the masters of the Immaterium. It was the Old Ones who first created the Webway that was later perfected and expanded by their Eldar servants, and they used its corrdiors to travel through the Immaterium instantaneously moving between pairs of Warp Gates established on many planets across the galaxy. A supposedly benevolent and gentle race, the Old Ones appear to have wished to nurture the younger intelligent races of the galaxy and protect them from the depredations of the C'tan. It is possible that the Old Ones are the same Old Ones that the Lizardmen worship in the Warhammer Fantasy universe, as in the Lizardmen Army Book it states that the Old Ones came from the stars and discovered the Warhammer World, then proceeded to terraform it and create intelligent races like the Slann, the Elves and the Dwarfs to live upon it. They were inherently patient as a race, and before attempting to journey out into interstellar space they made an extensive study of astronomy and astrophysics, which led them to eventually discover the Immaterium. At the time, the Immaterium was unaffected by the psychic emissions of other intelligent races (since there were so few), and so it was a calm and steady realm of existence. The Old Ones were able to exploit the Immaterium, allowing them to travel across the galaxy at a whim through the development of Warpspace tunneling technology and a network of Warp Gates called the Webway that instantaneously connected their far-flung interstellar colonies.
On their travels, the Old Ones seeded many other worlds across the galaxy with life, and encouraged the development of indigenous intelligent life on many more, including Terra.
It should be noted that the Old Ones in the Warhammer 40,000 universe may be related to the Old Ones of the H.P. Lovecraft mythos. The term "Old Ones" often applied to the Great Old Ones or the Elder Things which created life on Earth (Terra) in the H.P. Lovecraft mythos.
The War in Heaven
Before the creation of the Eldar, the Old Ones were at war with the Necrontyr over 60 million Terran years ago. One of the few already sentient races the Old Ones had encountered were the humanoid Necrontyr, who at the time were in the midst of a slow, sublight interstellar expansion to distant planets beyond the home star system. The lives of the Necrontyr were short and painful due to the deadly radiation of their world's sun. When they met the Old Ones, they developed a deep, jealous hatred of them due to their near-immortal lifespans. This resentment led to the first war ever fought in the galaxy. The Necrontyr's war was futile and they were forced back to their remote world in the outer rim of the galaxy's Halo Stars. The fury of the Necrontyr cooled over thousands of years of imprisonment, but they turned their hatred against all life rather than just the Old Ones.
The Necrontyr had studied their star for millions of years. In their quest for a weapon to use against the Old Ones, they found the C'tan. Gradually they managed to communicate with these ethereal beings of pure energy who fed on the solar energy of the stars, but the C'tan knew they would never be able to fully comprehend the material universe without a material body. So the Necrontyr built the living metal bodies from the alloy they called necrodermis that the C'tan are still adorned with. The C'tan were soon worshiped by the Necrontyr as their Star Gods, as their powers and intelligence were far beyond anything the Necrontyr had experienced before, even in their encounters with the Old Ones. As the C'tan became more manifest in their new physical bodies, they began to enjoy certain aspects of life more, including pain, suffering and slavery. Eventually, with the Star Gods themselves at their sides, the Necrontyr were ready to begin their war with the Old Ones anew.
The Necrontyr were vastly outclassed technologically and would not have posed much of a threat to the Old Ones, had not a twist of fate led them to discover the C'tan who dwelled within the hearts of stars across the galaxy, including the Necrontyr's own home star. The Necrontyr offered the C'tan physical bodies made of living metal called Necrodermis and renewed their ancient war with the Old Ones, now with the added might of their powerful C'tan Star Gods. The C'tan next offered the Necrontyr escape from the curse of their short lives. The C'tan offered to transfer the Necrontyr's minds into living metal bodies comprised of necrodermis, much like the C'tan themselves. The C'tan eventually tricked the Necrontyr into transferring their own consciousnesses into robotic bodies made out of the same necrodermis material. They did so and discovered to their horrors that their new bodies erased their psychic impressions in the Warp, effectively rendering them as soulless as the C'tan themselves. Whether the Necrontyr knew what they would lose by doing this will never be known, but the process essentially destroyed their race. They gained the immortality they had so craved but lost their free-will. Their minds were dulled and only a few members of the race, the Necron Lords, retained any independent thought. Unfortunately, the side effect of this process was that the Necrontyr, now calling themselves the Necrons, gradually lost the ability to feel any emotions at all and became the soulless, mechanical slaves of the C'tan, culling the sentient lifeforms the C'tan craved as sustenance in the terrible "Red Harvests." With the Necrontyr destroyed and the terrible new species called the Necron born, the C'tan began the war against the Old Ones once more with their legions of undying warriors, the cosmic confrontation that would later become known to the Eldar as the War in Heaven.
To combat these terrible foes, the Old Ones created new warrior races to battle for them, including the Eldar, the Rashan, the K'nib and the Krork, who may be the ancestors of the Orks. Knowing that the C'tan were vulnerable to psychic energies, the Old Ones designed their warrior species to be psychically linked to the Immaterium. Unfortunately, the raw emotions and collective unconscious beliefs of these new races altered the psychically-active Immaterium, creating their Gods and the daemons of Chaos. The introduction of these warlike and psychic races into the galaxy had the side effect of warping the Immaterium - the war, pain, suffering and destruction of the galaxy unleashed during the conflict was reflected in the Immaterium, literally changing its nature into that of the current chaotic and intrinsically hostile psychic dimension called the Warp. The innocuous entities which had naturally existed in the Immaterium were twisted into voracious and hostile predators. The Old Ones were ultimately devastated by the aftershocks of what their psychically-active creations did to the Warp, and are now believed to have either gone extinct or fled the galaxy, though the Eldar later built an interstellar empire by extending what remained of the Old Ones' Webway into a Warp tunnel network of their own. The C'tan empire could not counter this new form of psychic warfare. Eventually they became devoted to severing reality's relationship to the Immaterium in order to make psychic powers useless. Yet, even as the C'tan and the Necrons seemed to finally be driven back, the younger races' psychic instability allowed the Enslavers, a terrible species of Warp entities who could enslave the minds of psykers to create living gateways into the material world for others of their kind, to enter realspace. This Enslaver Plague further devastated the population of intelligent beings in the galaxy and ultimately forced the Old Ones into extinction or to flee the Milky Way. The Enslavers' depredations also made it impossible for the Necrons to gather enough sentients to feed the C'tan's ever-growing hunger for life energies. As a result, the galaxy was ultimately saved only because the C'tan and their Necron servants chose to enter hibernation on various "Tomb Worlds" scattered across the stars, where they would sleep for tens of millions of years until the galaxy was filled with enough sentient beings that the C'tan could feed upon them once more.
Other References to the Old Ones
The Old Ones are supposed to be identical to the Brain Boyz, the creators of the Orks. They are also assumed to be identical to the Old Ones mentioned in Warhammer Fantasy mythology, however recent editions of the games have removed most of the surrounding evidence for this to maintain more separation between the two universes.
- Codex: Chaos Daemons (4th Edition), pg. 18
- Codex: Dark Eldar (5th Edition), pg. 8
- Codex: Eldar (4th Edition), pg. 12
- Codex: Necrons (7th Edition), pp. 9, 24-25, 31, 61
- Codex: Necrons (5th Edition), pp. 6-7, 59
- Codex: Necrons (3rd Edition), pp. 9, 24-25, 31, 61
- Codex Titanicus (1989, 1st Edition), pg. 33, 52-53
- Liber Chaotica - Slaanesh by Marijan Von Staufer
- Realm of Chaos: Slaves to Darkness (1st Edition), pg. 215
- Warhammer 40,000: Rogue Trader (1st Edition), pp. 194-195
- Warhammer 40,000: Rulebook (4th Edition), pg. 139
- Chaos Child (Novel) by Ian Watson
- Eldar Prophecy (Novel) by C.S. Goto, pg. 151