Circa 1,000,000,000 BC - The Pilot civilisation develops advanced space travel and reaches for the stars.
Circa 100,004,000 BC years ago – The Pilot empire, already incomprehensibly ancient, erupts in a civil war that breaks out between two Jockey factions, the established faction that sticks to traditional inorganic technology and the heretics who have embraced a grotesque brand of biotechnology. Late in the war the heretics develop the xenomorph as their final solution.
Circa 100,000,000 BC - The Pilot Mo'la'khai of the traditional faction discovers the yautja homeworld. He studies them for some time before making contact. The yautja (predators) take him for a god. The Pilot gives them advanced technology and brings most of them onto his giant ship. He plans to use them against alien infestations, which have now overtaken both Pilot factions. Mo'la'khai deploys the yautja on a series of exterminating missions but he realizes that the xenomorph infestations are even worse then he thought ... his efforts are too little and too late. He places the yautja into sealed-off stasis chambers aboard his ship, as he tries to reformulate his plan. Unbeknownst to the Pilot, a facehugger has somehow gotten aboard. Its small size allows it to slip into the Pilot's hidden chamber and impregnates him even as the yautja slumber in stasis. The Pilot awakens to the stirrings of the chestburster and before he can do anything it breaks free. With his last ounce of strength, Mo'la'khai snaps the newborn alien's neck before dying*. The ship floats through space.
50 million years elapse
Circa 50,000,000 BC - the ship's main generator goes off-line. The majority of stasis chambers containing the Yautja are powered down. They awaken and wait for the Pilot to summon them. For obvious reasons, he does not. They leave their stasis chambers and think that the Visitor has left them, though they believe he will return one day. The yautja board ships that the Pilot specially designed for them to use on missions, and spread out into space. The Pilot ship, still on autopilot, drifts off further into the void.
1986 - Mankind's first reported encounter with the yautja
2122 - Mankind's first reported encounter with Linguafoeda Acheronsis ("foul tongue from Acheron")
2350 - Major Li's encounter with the yautja and Linguafoeda
*Though much stronger than a human, a Jockey would be considered quite frail compared to a yautja.
