- "There are beings in the universe billions of years older than either of our races. Once, long ago, they walked among the stars like giants...vast and timeless."
- – Delenn
The First Ones were a group of ancient races that achieved sentience billions of years before any of the "Younger Races", such as the Minbari, Humans or Centauri.
The most well known races among the First Ones are the Vorlons and the Shadows, who after most of their contemporaries passed beyond the Rim, into the void between galaxies, opted to stay behind and act as guardians and shepherds for the younger races.
History
The First Born
Before even the First Ones were young, there was a race in the galaxy born to be naturally immortal. The first among them to rise to sapience was an individual named Lorien. He, along with the few others of his kind found the Vorlons, the Shadows and all of the other races later known as the First Ones when they were infant races. Over time, Lorien and his kin helped them grow and develop and although most of them eventually died out, the ones that went on flourished, becoming vast and powerful beings. Creating great empires, exploring beyond the Rim and like Lorien's people before them, they found even younger races and became their teachers and guardians.
Guardians of Order & Chaos
Like all things, this did not last forever and gradually, over the course of a million years, most of the First Ones, along the few of Lorien's people who did not perish though injury or illness, left the galaxy, never to return and some simply disappeared. Of those few who were left behind, Lorien was the only Firstborn to remain while among the handful of First Ones that did not leave, the Vorlons and Shadows were the eldest and they took up the responsibility as the sole guardians and protectors of the younger races. Others, such as the Walkers of Sigma 957 took little interest in the affairs of the younger races, if they noticed them at all, yet they stayed, hidden or asleep waiting for the day that they would be needed. Lorien eventually withdrew and dwelt deep beneath the planet that would become known as Z'ha'dum.
A War of Ideology
Though the Vorlons and the Shadows followed diametrically opposite ideologies on what is the best way to help and to teach the younger races, they both agreed to respect each other's position, maintain the balance between them and abide by rules of engagement. However, at some point, one or both of them decided that their way was the right way and the only way and so began a conflict of ideology that would last for over a million years. Although the two guardian races were technically at war, neither attacked the other directly, choosing instead to fight their battles though the hearts and minds of the younger races in their care. On the side of the Shadows, they fostered conflict and hardship with the belief that it would both breed stronger races and weed out those too weak to survive. The Vorlons on the other hand believed in rigid order and obedience and had already manipulated many of the races to see them a beings of light, messengers of the universe and even Gods. Rather than letting nature take it's course, the Vorlons actively adjusted the genetic evolution of certain races and in time, even created telepaths that could be used to counter Shadow Technology. For a time, the few remaining First Ones helped the younger races fight back against the destruction and chaos wrought by the Shadows, but they were only ever beaten back, never destroyed. Each time they were defeated and driven off their homeworld of Z'ha'dum the Shadows would always return, believing that they were showing respect for Lorien. The last great war fought between the remaining First Ones took place around ten thousand years before the Third Age of Mankind and it would be the last time that the other First Ones would walk openly among the younger races. Nine thousand years later the Shadows once again returned to Z'ha'dum and began to rebuild their power and stretch forth their hand to begin another war among the infant races. This time however, they were defeated by an alliance of worlds including the Minbari, Hyach, Vorlons and the few remaining First Ones. When the war was finished it was thought that all the other First Ones having grown tired of the endless conflict, went away, leaving only the Vorlons behind.