Genesis

"There's a formalness and precision to it all. It seems… artificial, but still organic."

- Linda-058, after she and Blue Team arrive on Genesis

Genesis is a Forerunner world, artificially constructed by the Builders.

History
After the destruction of the Ur-Didact's ship, Mantle's Approach, at the hands of John-117 and the smart AI Cortana, the ship and Cortana were pulled into slipstream space as a last ditch effort for the ship to escape destruction. Unbeknownst to the Master Chief and the UNSC, Cortana and Mantle's Approach ' s debris crash-landed on the Genesis, where Cortana was uploaded into the Domain and "cured" of her rampancy. While in the Domain, Cortana came to the conclusion that the Mantle of Responsibility was meant to be claimed by herself and other artificial intelligences, not humanity, as the Forerunners had originally intended. Once uploaded on Genesis, Cortana seized control of the world from its monitor—031 Exuberant Witness—with the help of the Warden Eternal. Once in control, Cortana began activating the Guardians across the galaxy, calling them to Genesis to rally before dispersing them to populated worlds as a means to enforce the Mantle and her rule upon all races.

List of appearances

 * Halo 5: Guardians