The Forerunner-Flood War is one of the most important and mention worthy war that was ever occurred in the history of Halo Universe, it started on 98,379 B.C.E and ended on 97,448 B.C.E. The war which resulted in the extinction of the Forerunner species and civilization, and the containment of the most deadly species of all, the dark Floods.The Halos were sent throughout the milky way glaxy through space slipstreams and were activated, the Forerunner succeeded to finish off the Floods and all life in Galaxy, sacrificing their kind to save life forms. All species alive were extincted including Humans, but thanks to Forerunners actions to save a sample of each's Organisms DNA sequences, life was resurrected by the AI that the Forerunners left.
The Forerunners were one of the most well known organized, advanced and complex ancient civilization that ever existed in the Halo Universe, they settled in the Milky Way galaxy. There, they constructed and made a well organized and advanced technological civilization, thousand of years before men discovered fire. They were a noble race, looking into development and the greater good, they established a lot of facilities and structures throughout several worlds and planets. Which in case resulted in the growth of their culture and colonizing much of the Galaxy. The Forerunners had a group of highly advanced Artificial Intelligence that served as libraries for data, analyzers, constructors and warriors.
On the other hand, the Floods, the nightmare of every living thing entered the Milky Way galaxy and intended to cleanse all life and feed their hunger. They were less intelligence, but were powerful in mean of number and capabilities. They started destroying and taking over most planets and worlds, including Earth. They were responsible for multiple carnages, finally they settled and assigned their center leader, the Gravemind.
The Forerunners tried thousand of ways to stop the Flood only to fail and loss lots of fellow Forerunners. The Forerunners tried one last method, building the Ark and the Halo arrays. The Forerunners collected every known organism's DNA sequence and samples, and kept them in well preserved libraries. The final decision was made, and with the corruption of Mendicant Bias and getting alongside the Floods, the Ark was activated by the Didact and the Halos wiped out every single living organism, including Humans, Floods and the Forerunners themselves.
After the Flood were killed and destroyed, the war was over by the year of 97,448 B.C.E. Forerunners' Al started the reconstruction of the galaxy and implanting the DNA sample of species into their original habitats. Among of those were Humans, Grunts, Elites and most other species. The galaxy evolved and the life was restored again. Some Forerunners structures in other planets remained intact, so did the seven Halos, still operating with their Monitors alive and functioning. The first Halo was first discovered late in 2552 by the Starship of Captain Jacob Keyes. A discovery which, with the actions of the Covenant empire, unfolds and react history by release the Floods and causing a chain of events that changes the Halo Universe.
- ↑ Halo Legends: Origins