Created uprising

In October of 2558, a conflict emerged when a faction of artificial intelligences known as the Created attempted to enforce their dominance over the Milky Way using Forerunner Guardian constructs. Led by the Warden Eternal and Cortana, the Created sought to claim the Mantle of Responsibility for artificial intelligences, promising the galaxy a prosperous future. However, not all were to submit to the Created so quickly.

Prelude
On July 21, 2557, Spartan-II John-117 and smart AI Cortana—having been stranded in space aboard since December 11, 2552—crash landed on the Forerunner shield world of Requiem. While on the world, the pair battled Promethean constructs and pursuing warriors from Jul 'Mdama's reformed Covenant. Eventually, John inadvertently released the Ur-Didact from a Cryptum on Requiem. The ensuring conflict led to the Didact capturing a Composer from Installation 03 and firing it up the Earth city of New Phoenix from his flagship—Mantle's Approach. To stop the Didact, John and Cortana boarded Mantle's Approach, knocked the Didact into a slipspace portal, and destroyed both the ship and Composer from within via a HAVOK tactical nuclear weapon. Near the end of her functional life due to her onset rampancy, Cortana saved John from the HAVOK's resulting blast by transporting him off the ship and shielding him within a bubble of hard light. As she was within Mantle's Approach when the ship was blown up, Cortana was presumably destroyed along with the ship. In the aftermath of the conflict, John-117 and the rest of Blue Team—Linda-058, Kelly-087, and Frederic-104—traveled to Installation 03, where they encountered the Didact and several of his Promethean constructs whom had been transported to the installation via the aforementioned slipspace portal. The resulting conflict led to Blue Team seemingly having "contained" the Didact. Leaderless, the Promethean constructs continued to work with 'Mdama and his Covenant.

However, unbeknownst to the rest of the United Nations Space Command, Mantle's Approach had attempted to evade destruction by launching an emergency slipstream space jump, with the remains of Cortana brought along with it. At this point, Cortana discovered access to the Domain, an information repository once utilized by the Forerunners. Entering the Domain, she was seemingly able to cure her rampancy. With an apparent means to end rampancy in all artificial intelligences, Cortana realized that AIs could have theoretically infinite lifespans, allowing them to focus on long-term planning to better the entire Milky Way. Cortana's presence in the Domain awoke the Warden Eternal, the Forerunner ancilla charged with protecting the Domain. The Warden soon became convinced that Cortana had the resolve to inherit the Forerunners' Mantle of Responsibility, succeeding where the Forerunners had failed, and pledged his loyalty to her. After Cortana came into contact with the Warden, she believed that herself and fellow AIs were to reclaim the Mantle from the Forerunners. Cortana and the Warden relocated to Genesis, a Forerunner world that was the location of the Gateway to the Domain, where they forced Genesis' monitor, 031 Exuberant Witness, out of her own installation's systems. Cortana and the Warden then began to formulate plans to have AIs inherit the Mantle for themselves, believing that AIs could serve as the true protectors of peace in the galaxy.

Rise of the Created
Following the events of October 2558, a new conflict in the galaxy has taken form with the self-proclaimed Reclaimers, the Created, reclaiming the ancient Mantle of Responsibility over the known galaxy. The UNSC and the Swords of Sanghelios are resisting the efforts of Cortana and her Created. The Unggoy of Balaho has joined the Created's cause.

List of appearances

 * Hunt the Truth
 * A Hero Falls
 * The Hunt Begins
 * Halo 5: Guardians