From Halopedia, the Halo wiki
- In 150,000 BCE (approx.), the Forerunners are claimed by some records to have risen as the preeminent species in the Milky Way Galaxy by advancing technological discoveries gathered from the remnants left by prior ancient races. Believing themselves responsible for the lives of all those less advanced then they, the Forerunners initiate the Mantle.[note 1]
- Humanity is believed by the Forerunners to have "moved their interstellar civilization outward along the galactic arm" around this time, possibly to escape Forerunner control.
- ^ This entry, originating from the Halo Encyclopedia, is of dubious accuracy in light of information from The Forerunner Saga, in which the Forerunners are stated to have been spacefaring for millions of years (albeit having experienced a number of technological dark ages and large-scale record loss events over the course of this period) and that they held the Mantle since 10,000,000 BCE, having forcibly seized it from the Precursors. However, the Encyclopedia notes that "all Forerunner era dates are approximate, based on available translation and scattered historical data", which provides a canonical explanation for the possible inaccuracies of this entry.
- ^ Halo Encyclopedia, page 26
- ^ Halo: Cryptum, "chapter 1", ("She responded that to the best of Forerunner research, humans had indeed first arisen on Erde-Tyrene, but over fifty thousand years ago had moved their interstellar civilization outward along the galactic arm, perhaps to flee early Forerunner control. Records from those ages were sparse.")