97,445 BCE

In approximately 100,000 BCE, the Forerunner-Flood war came to a close.


 * The Librarian visits the San 'Shyuum homeworld Janjur Qom to collect specimens in order to protect the San 'Shyuum species from the Flood at the Ark. This sparks unrest among the San 'Shyuum population, who soon begin a rebellion against the Forerunners.


 * The Didact is resuscitated from his exile in a Cryptum by Bornstellar Makes Eternal Lasting. They later make their way to Janjur Qom, where the Didact is interrogated and eventually executed by the Master Builder, but lives on in Bornstellar's body through an imprint acquired in his mutation. Shortly afterward, the Master Builder authorizes the use of a Halo ring to put down the San 'Shyuum rebellion by sterilizing the entire system. For this, the Master Builder is placed on trial and the Forerunner Council decides that the Halo rings be decommissioned.


 * The Forerunner AI known as Mendicant Bias, having been seduced by Gravemind and descended into rampancy, returns from his 43-year absence with one of the Halo rings and launches an assault on the Forerunner capital, presumably crippling the Forerunner government. The Didact, having survived the battle, assumes command of Forerunner military forces after a thousand years of exile.


 * Later, Mendicant Bias allows the Flood into the Maginot Sphere, which gives them the opportunity to attack the Forerunners' inner colonies.


 * Mendicant Bias attempt to assault the Ark, but is stopped by Offensive Bias's fleet and is defeated. Part of Mendicant Bias' personality construct remain in a Keyship which would eventually end up on the San 'Shyuum homeworld. As the two AIs fight each other, the Forerunners fire the Halo Array. The activation is a last resort intended to end the Forerunner-Flood war, killing all sentient life within three radii of the galactic center, including any Forerunners not located on The Ark or within Shield Worlds.


 * Some time after every sentient species, carefully indexed in the Ark, is returned to their homeworlds as a part of the Library Project, the Homo sapiens species begins migrating out of Africa.

Trivia

 * 343 Guilty Spark put the date of the firing of the Array as the year 97,448 BCE, though it should be noted that he measured it on Installation 04's year, not the 365.25 day Earth calendar.