The Forerunners

The Forerunners are a highly advanced species that existed over 100,000 years ago as the dominant species in the Milky Way Galaxy. Around 150,000 BCE, the Forerunners took up an ethical code of conduct they called the 'Mantle'. Bridging the social starta between an interstellar Marshall Plan and a religious, but benevolent, stewardship, the Forerunners took responsibility for the protection and cultivation of the species and planetary systems within their domain. With this grand purpose, their social structure evolved into caring and community-minded populace. Their central government was entirely didacted by the Mantle, as were the religious beliefsof individuals Forerunners. However, inspiring peace throughout their domainby minimizing their military capacity and disarming their weapons cache proved to be a costly approach for the Forerunners when the new alien threat emerged.

The Forerunner social structure:

1) Builders

2) Miners

3) Life Workers---The Librarian being the highest ranking

4) Warrior-Servants---The Didact being the highest ranking

5) Engineers

Builders being at the very top and Engineers being at the very bottom.

During the Forerunner-Flood War, the Maginot Sphere was created to protect the Forerunners inner-most colonies from the Flood. Near the end, the seven Moniters chosen by the Librarian, were sent to their individual Halo rings to continue study of Flood spores.

Military Defeat: In a desperate measure, the Forerunners' armada was ordered to immediately begin a full planetary bombardment on infested worlds. Many Forerunners were unable to be evacuated before the bombardment commenced. This meant Pyrrhic victories for the Forerunner military, who were killing their own people in order to save them. Where bombardment was unable to be undertaken by naval garrisons, Forerunner population centers activated localized weapons of mass destruction, committing mass suicide.

As the Flood parasite continued to infect most the galaxy, the Forerunners finally accept the fact that the only way to stop the Flood is to eradicate all sentient life in the galaxy. The plan to wipe out all sentient life was carried out starting with the evacuation of as many of the inner colonies as possible to the Ark. The Halo Array would wipe out all recorded sentient life in the galaxy, ironically this was done to preserve life. After the rings were fired, the sentinels would return the many species to their homeworlds. The Forerunners disappeared after the Halo Array was fired, and haven't been seen since.

Tragic Love: The Librarian and the Didact's conversations were achieved in the Terminals aboard the Ark centuries ago and reveal their tragic love. When the Librarian was on Earth, the Didact pleaded with her to return to the safety of the Maginot Sphere, but she was devoted to her vocation and remained in harm's way in order to save more species, going far beyond the call of her assignment. Eventually, the Librarian pleaded with the Didact to activate the Array in order to destroy the Flood. The Didact stalled the enemy Flood as long as he could while seeking an alternative way of destroying it and rescuing his love. The Forerunners created an AI, and destroy it. The Librarian strongly objected to this plan, calling it suicidal, and begged the Didact to ignore her welfare in favor of the greater good. She demanded that he fire the Array but her pleas fell on deaf ears. the Didact would not abandon her.

Mendicant Bias then approached the Gravemind, but the plan backfired. He defected to the Flood and led an attack on the Forerunners that broke through the Maginot Sphere.

The Librarian witnessed this attack from outside the Maginot Sphere, effectively trapped beyond the action. She desperatly sent word to the Didact, warning her love of the Flood horde that was coming for him. The Librarian remotely destroyed all of theportals and other installations that would lead to the Arkso that it would not fall into the grasp of the Flood, but this also made it impossible for her to escape. She begged the Didact one final time to fire the Array. He replied that her observation of the Flood armada confirmed the information he'd been searching for---her location.

Unable to reach her, and she unable to escape, a final message was exchanged from the librarian to the didact:

"My work is done. The portal is inactive, and I've begun the burial measures. soon there'll be nothing but sand and rock and normal signatures. You should see the mountain that watches over it. That's where I will spend what time is left to me.

Did I tell you? I built a garden. The Earth is so rich. A seed falls and a tree sprouts or a flower blooms. There's so much potential. We knew this was a special place because of them, but unless you've been here, you can't know. It's [Eden].

The thing is listening. Its [thinking dead] are babbling---laughing through every channel they can find. Be proud. The Mind claims victory, yet it still doesn't suspect, You've outwitted it, my love. And now you can destroy it.

But you cannot save me."

The Didact finally fired the Halo Array

The final resting place of the Librarian was a small, nondescript blue sphere called Earth. This planet was the location of the only Portal that was spared the Librarian's destruction. The Forerunner's affinity for the human race was finally explained as the unlikely progeny of this love story:

"The anomalous world is in a perilous location beyond the line. The secretsit holdsmust be preserved, plans within plans within plans. The inhabitants;these unique denizens, must be researched. They may hold answers to our own mysteries.

What irony that we discovered this treasure, only at the end of things. But what fortune that we still had time to save them. The thing we built on that world will vouchsafe their lives, but perhaps one day it will be used for its intended purpose. If the plan succeeds, and they are saved, it will be a good world.

If the plan fails, and the adversary succeeds, it will remain an enigma forever with no one left to reclaim it."

Just before the firing of the Array, Mendicant Bias' defection to the Flood ended with a final showdown between Offensive Bias & Mendicant Bias at the edge of the Maginot Sphere.

The battle ended with Offensive Bias sacrificing itself and Mendicant Bias being nearly destroyed. The remains of Mendicant Bias being trapped within a Dreadnought later seen onboard High Charity. Mendicant was the true leader of the Covenant, by leading them to pointlessly wipe out all life in the Galaxy.