They measured technological advancement in a succession of Tiers. Their technological capacity was without equal, in areas such as the understanding of slipspace, energy manipulation, artificial intelligence and astroengineering. The Forerunners' society was based on caste-like strata known as rates, with a dedicated military class which included both naval elements and ground forces. They derived their authority from the Mantle, their pledge to watch over and preserve all life in the galaxy. The Forerunners were an ancient race who thrived as the dominant civilization in the Milky Way galaxy, organizing their ecumene over millions of terrestrial planets. The conflict ended the Forerunners' eons-long rule in the galaxy most of their ecumene having fallen to the Flood, the few remaining members of the species went into exile after completing the repopulation of the galaxy's sentient species from specimens preserved at the Ark. The Forerunners concluded the war in 97,445 BCE with the creation and activation of the Halo Array, seven superweapons that purged the galaxy of all sentient life in order to stop the Flood. It was started on G617 g1 around 97,745 BCE and lasted approximately three centuries. The Forerunner-Flood war, known as the Flood war, was a pivotal galactic conflict that occurred between the Forerunners and the Flood parasite. a deeply alien threat they called simply the Flood.' - Cortana Something they never expected, never prepared for. Like all great civilizations, they faced a sudden and dire turn of events. ' A hundred thousand years ago, a great civilization existed in this universe. Near total: Most are killed by the activation of Halo Array while few survive and depart the galaxy.Įxtremely heavy: All Flood and Flood biomass is destroyed except for those contained in secure Forerunner facilities all Precursor constructs destroyed Numerous star roads and other Precursor constructs.Millions of captured unarmed superluminal vessels.Offensive Bias (constructed late in the war).Near extinction of the Forerunners and end of the Forerunner ecumene.

Flood halo