Conservation Measure

The Library Project, also known as the Conservation Measure, was a massive undertaking by the Forerunners to index and preserve biological diversity in the Milky Way Galaxy during the Forerunner-Flood War.

History
When the possibility of the Halo Array was first proposed, the Librarian responded with outrage at the Builder's idea of defeating the Flood by committing galactic genocide, and petitioned the Master Builder and the Council to take measures to preserve the galaxy's life-forms in the event of the Halo Array's firing. As the Lifeworkers could halt medical science if they abandoned their duties in protest, Master Builder Faber concluded that it would be less expensive to give in to the Librarian than fight her, so he agreed to her request. There were quite a few problems at first, mainly with regards to categorizing the races into specific categories.

As it became increasingly obvious that the Array would be the only means to defeat the emerging Gravemind, the Librarian urged her husband, the Didact, to fire the Array. But the Didact, still clinging to the Mantle and unwilling to kill his wife with the Array, delayed activating the Array. In an effort to force the Didact's hand, and knowing that the Flood would soon find the Ark with Mendicant Bias' help, the Librarian destroyed her keyships on Earth, stranding her in the Array's radius of fire. Without any option left, the Didact fired the Array.

After the Flood was defeated, automated systems on the Ark began the process of repopulating the galaxy in a stage referred to as the reintroduction, sending all the races back to their respective homeworlds. While a success, the Library Project also sent each race back to a Tier 7 scale, forcing the sentient races to start over. The period directly after the reintroduction was referred to as "the dark time", as some of the indexed species never recovered and subsequently became extinct.

Two reintroduced races (the San 'Shyuum and Sangheili) would end up worshiping the Forerunners as gods, something the Forerunner hardly anticipated. The data concerning the Library Project was preserved at the Ark, a revelation which surprised 343 Guilty Spark.

List of appearances

 * Halo 3
 * Halo: Legends
 * Origins
 * Halo: The Flood
 * Halo: Cryptum