Editing Forerunner

Roughly nine thousand years after their war with the humans, a Forerunner survey team on the planet [[Seaward]] came into contact with the Flood. After this first contact, the Forerunners immediately recognized the great danger that the Flood posed to the entire galaxy and attempted to contain them. Even though they knew the power of the Flood, the principles of the Mantle forbade them from destroying it. As such, the attempt to contain the Flood was a failure, as they tried methods more suited to disease control instead of all-out warfare, trying to contain and quarantine the Flood rather than attack and destroy it outright. They did not start war until it was far too late.<ref name="h3terminals">'''Halo 3''', ''[[Terminal (Halo 3)|Terminals]]''</ref>

When the Forerunners were unable to contain the Flood outbreak, the galaxy entered a state of war. The Forerunners desperately studied the Flood, looking for any exploitable weakness. As the Forerunners soon realized that conventional naval tactics were ineffective against the parasite's onslaught, they developed new weapons and tactics to combat the Flood. The [[Sentinel]]s were deployed as a means of maintaining the Flood through surgical, localized tactics. Eventually, the [[Forerunner fleet]] began to enact premature stellar collapse within compromised planetary systems, causing [[supernova]]e to engulf entire worlds.<ref>'''Halo Encyclopedia: The Definitive Guide to the Halo Universe''', ''page 169''</ref> However, these tactics proved only to slow, but never stop the expansion of the Flood. Even at this late hour, the Forerunners were reluctant to use the Halo Array, believing that they should continue to embrace the Mantle and to protect life rather than to destroy it. This led to great stretches of anguished debate and even civil war.<ref>'''Halo Encyclopedia: The Definitive Guide to the Halo Universe''', ''page 172''</ref>{{clear}}

===Firing of the Halo Array===

{{Main|Great Purification}}

{{Quote|After exhausting every other strategic option, my creators activated the rings. They and all additional sentient life within three radii of the galactic center, died, as planned.|[[343 Guilty Spark]] on the fate of the Forerunners.}}

After nearly three centuries of war, what had been a relative stalemate quickly began to turn in the Flood's favor. The [[Gravemind]] managed to convince [[Mendicant Bias]], the AI in charge of Forerunner defense, to unite with the Flood and turn its military assets against its creators. With the Flood growing at an exponential rate, entire [[thema]]s of the ecumene were overrun; the Flood-infested regions, known as [[Burn]]s, soon covered two-thirds of Forerunner space.<ref>'''Halo: Silentium''', ''page 190''</ref> The Forerunners eventually resorted to the [[Maginot Line]], leaving all systems beyond the [[Orion complex]] to fend for themselves.{{Ref/Reuse|jatkrula}} Meanwhile, the Flood and the Graveminds developed into more capable and [[Key Mind|powerful forms]], enabling them to tap into Precursor [[neural physics]] and control Precursor artifacts scattered across the galaxy. The Forerunners possessed no effective defense against these constructs and the Flood won most naval engagements as a result.<ref name="sil214">'''Halo: Silentium''', ''pages 214-215''</ref>

===Exile===

{{Quote|no=two|q1=We will do what we can with what we are given. But what of you? Where will the Forerunners live?|Riser|q2=I do not know, not yet. All I know for certain is that we cannot return to these places. We have already meddled too much in the affairs of others.|IsoDidact|[[Riser]] and the [[IsoDidact]] as they bid farewell on a repopulated Earth.{{Ref/Reuse|rebirth}}}}

===Artifact involvement===

{{Quote|Mankind is outmatched. When Reach falls - and it will fall - our annihilation is all but certain. Unless...we can glean from this artifact a defense against the Covenant. A game-changer. On the level of the conical bullet in the nineteenth century, or faster-than-light travel in the twenty-third.|Dr. [[Catherine Halsey]], after decrypting [[Babd Catha Forerunner complex|the Forerunner artifact under]] [[SWORD Base]].}}

Forerunner artifacts became instrumental to beginning and ending the [[Human-Covenant War]]. First contact was made when humanity's Reclaimer status was discovered by the Covenant, who did not understand that they were being labeled as Forerunner objects. The [[Hierarchs]] of the Covenant soon learned humanity's status as apparently living descendants of their supposed gods, and found it potentially destructive to their religion. Thus they decided to hide this information from the general population and ordered that humanity be eradicated, a goal in which they nearly succeeded.{{Ref/Reuse|ch}} Battles were fought often with relics at the center of the conflict, sometimes risking giving the Covenant victory early, other times hindering them and turning in favor of humans due to the Covenant's reluctance to damage Forerunner treasures. Many relics were destroyed by humans often as traps for Covenant or to keep them from falling into enemy hands.<ref>'''Halo Wars''', campaign levels ''[[Reactor (Halo Wars level)|Reactor]]'', ''[[Escape (Halo Wars level)|Escape]]''</ref><ref>'''[[Halo: Evolutions - Essential Tales of the Halo Universe]]''', ''[[Dirt]]''</ref>

==Technology==

The Forerunners' technological achievements were almost without parallel in the known galaxy with them being rivaled by ancient humanity and the San'Shyuum before the latter two species defeat in the human-Forerunner wars and with only the Precursors being known to surpass the Foreunners technologically. They managed to create solidified surfaces out of light by using technology known as [[hard light]], use [[Slipstream space|slipspace]] to [[Slipspace translocation|teleport]] between locations almost instantaneously, and create numerous forms of advanced machinery. Another of their greatest achievements is their ability to initiate premature stellar collapses of stars and create planets in less than 10,000 years. The [[Halo Array]] and the [[shield world]]s are, above all others, the most significant pieces of surviving Forerunner technology. The planet Onyx and its inner [[Dyson sphere]], [[Trevelyan|Shield World 006]], in particular demonstrated both their ability for engineering on a grand scale, and their near-transcendent grasp of slipspace technology. Forerunner technology is remarkably resilient, being able to remain intact for over a hundred millennia.<ref>'''Halo: Combat Evolved'''</ref>

===Weaponry===

The Forerunners used a broad variety of weapons, encompassing various forms of [[directed energy weapon]]ry as well as [[AI suppressor|electronic warfare]] and offensive technologies based upon [[Confinement field|energy fields]]. Forerunner energy weapons proved to be very effective when battling the Flood, burning Flood forms to the point that they cannot be revived by [[Pod infector|infection forms]]. Additionally, after the Flood's emergence, certain weapons were designed to disintegrate their targets upon inflicting a critical hit, preventing the Flood from making use of any biological matter.{{Ref/Reuse|halo 4}}

===Art and architecture===

Forerunner architecture incorporates heavy use of geometric angles, usually at either extremely sharp degrees - Forerunner buildings are usually trapezoidal - or at forty-five degree angles. Most Forerunner architecture is constructed with a special type of silver-gray metal that resists deterioration, bullets, plasma bolts and fire, as made evident by Forerunner structures standing in pristine condition 100,000 - 150,000 years after they were built. However, their resistance to heavy [[plasma]] fire is limited; concentrated plasma discharge is capable of destroying some Forerunner architecture.<ref>'''Halo: Ghosts of Onyx''', ''page ???''</ref><ref>'''Halo 2''', campaign level ''The Great Journey''</ref> Other structures and [[Council ship|certain starships]] were built with a golden-bronze colored metal.

===Astroengineering===

{{Main|Astroengineering}}

While the Forerunners' architectural and technological prowess is legendary, their masterpieces also extended to the fields of stellar and planetary engineering.