~97,745 BCE

Around 97,745 BCE, nearly nine-thousand years since the Flood disappeared from the galaxy during the Human-Forerunner Wars and three-hundred years before the Great Purification, the Flood were first observed at the edges of the galaxy on the planet Seaward, a Forerunner colony world.

~97,745 BCE - 97,445 BCE

The Forerunner-Flood War was a military engagement between the Forerunner species and the Flood that took place over approximately three-hundred years from 97,745 BCE until 97,445 BCE.

~97,495 BCE

The release of the Primordial was an unintended consequence of the test-firing of a Senescent Halo, Installation 07, by the Master Builder and Mendicant Bias in the Charum Hakkor system during the Forerunner-Flood War, approximately fifty years prior to the end of the war and the Great Purification.

~97,455 BCE

Following the Didact’s self-imposed exile one thousand years prior after losing the political battle over the Forerunner defense plan against the Flood, the Didact is resurrected from his cryptum on Erde-Tyrene by Forerunner Manipular Bornstellar Makes Eternal Lasting, and humans Chakas and Riser.

~97,455 BCE

The Battle of Janjur Qom was a brief conflict between the San’shyuum and Forerunners on the quarantined San’shyuum homeworld of Janjur Qom several years prior to the firing of the Halo Array during the Great Purification in 97,445 BCE.

~97,455 BCE

After the Revival of the Didact and his exploration of the Charum Hakkor system with fellow Forerunner Bornstellar Makes Eternal Lasting and humans Riser and Chakas, the Didact and crew traveled to the quarantined San’shyuum homeworld of Janjur Qom to try and unlock more memories in their quest for understanding.

~97,454 BCE

The Fate of Maethrillian was a large-scale but brief battle between the Forerunners and the Halo Array under command of Mendicant Bias several years prior to the firing of the halos during the Great Purification in 97,445 BCE.

~97,454 BCE

In the aftermath of the Fate of Maethrillian and destruction of the Forerunner ecumene, Zeta Halo implemented it’s security measure designed to prevent the ring from falling into enemy hands and performed a slipspace jump into another system and put itself on a collision course with a nearby planet.

~97,450 BCE

After the Master Builder captured the Didact over Janjur Qom, he decided to dispose of the Didact on a derelict Forerunner ship with a handful of other political prisoners in an area of Flood-controlled space known as a Burn.

~97,445 BCE

The Battle of the Greater Ark was one of the final battles of the Forerunner-Flood War and saw the decimation of almost all remaining Forerunner forces just prior to the firing of the Halo Array during the Great Purification in 97,445 BCE.

~97,445 BCE

The behavior of the Ur-Didact following his encounter with a Gravemind and return to the Forerunner civilization became more erratic and harder for the IsoDidact and Librarian to cope with as the Forerunner-Flood War continued.

~97,445 BCE

The Great Purification was the final event of the Forerunner-Flood War, purging the entire Milky Way galaxy of all sentient life, including Forerunners, the Flood, and any other species that may have survived the Flood infestation.

~97,300 BCE

Over one-hundred years after the Great Purification, the few Forerunners remaining on the Lesser Ark became aware that the firing of the Halo Array may have had a detrimental effect on the Domain, and proceeded to the former Forerunner capital of Maethrillian to attempt to restore it.