The Forerunners “re-seeded” (essentially a form of repopulation after activating a Halo) various species, exiled their few remaining members, and passed the Mantle to the humans. Losing the war, the Forerunners constructed and activated the titular Halo rings, which were designed to destroy all life that the Flood could potentially prey upon - starving the Flood, ensuring its demise. Without the humans around, the Flood returned and went to war with the Forerunners. The Librarian, a Forerunner, looked over humanity. The Forerunners brought humanity back to the stone age, stripping them of their interstellar travel. The humans defeated the Flood but lost to the Forerunners and their Promethean warriors (led by the Didact). Believing humanity was pushing its luck and reaching too far, the Forerunners also went to war with the humans in order to stamp them out. Humans eventually discovered the Flood, which started a brief war. With the Precursors gone, millions of years passed with the Forerunners in charge. The Didact, a Forerunner captain Image: 343 Industries via Halopedia Turning mostly to dust, the Precursors eventually became the Flood, the zombielike parasite that ruins the back half of most Halo games. There’s some debate about whether the Precursors planned to destroy the Forerunners or the Forerunners attacked unprovoked. Believing they were the superior creation, the Forerunners obliterated the Precursors and took up the Mantle of Responsibility for themselves. The Precursors had apparently decided to pass the Mantle onto the humans - letting them dictate the flow of life in the universe - rather than the Forerunners. In the Forerunner-Precursor war, the Forerunners destroyed their creators. They’re not all evil, but they are primarily responsible for nearly every problem in the Halo universe: the Flood, the Halo rings, and - to some extent, out of their control - the Covenant itself.

They were positioned to be the Precursors’ original successors, and, at one time, the most powerful species in the universe. The Forerunners were humanity’s biggest rivals and serve as the primary antagonists in 343 Industries’ Halo games. The Precursors helped shape and evolve humans, the Forerunners, and many other races using the Mantle of Responsibility, a creation philosophy. The Forerunners get all the credit in the Halo games, but the Precursors came before, as their name implies.

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