Domain

"The records don't always stay the same. Sometimes they change. It is not known why." "Like real memories."

- Bornstellar-Makes-Eternal-Lasting and Chakas discussing the Domain

The Domain was a vast information network used by the Forerunners. It contained the ancestral records and all knowledge of the Forerunner civilization.

Overview
The Domain was apparently not located within normal space-time, or tied to any particular location or system, as mature Forerunners were able to connect to the Domain through their personal armor anywhere, regardless of distance. The Domain was also central in major Council proceedings, such as a political trial. Among other things, it was used by the judges to store archival and accounting material, assess precedent, and to verify witnesses' testimonies. Contender-class ancillas such as 05-032 Mendicant Bias were connected to the Domain upon their activation.

There was a mysterious quality to the Domain; its exact nature or origin remains largely nebulous. Sometimes, the records contained within the Domain changed for an unknown reason. The changes were regarded as sacred, and were never reversed or corrected. However, due to these anomalies, the Domain was not commonly used as means of communication; messages could be inexplicably altered on the way. The Domain appears to be somehow related to a Forerunner's subconscious; according to an ancilla, Forerunner scholars theorized that the dreams of early Forerunners accessed the "ground" that the Domain is built upon. The Didact mentioned that that the Domain sometimes had a "broken-mirror aspect", making it appear as if one's experience of visiting the Domain was the product of their own mind.

Further adding to its mystical nature is that in some cases, the use of an armor's interface was not even necessary to contact the Domain; when Bornstellar Makes Eternal Lasting approached Janjur Qom, the Domain opened to him for a brief instant; at first he described the experience as "deep" and "appropriately shapeless", but it soon took form, shaping into a coherent whole around his consciousness. Through this experience, Bornstellar felt the essences of everyone who had ever visited the Domain reach out to him, urging him to preserve the history of the Forerunners which would soon come to an end. When the Didact confronted his main opponent, Forthencho, the Lord of Admirals after the final battle for Charum Hakkor, he mentioned that "But to all of us there is a time like this, when the Domain seeks to confirm our essences, and for you, that time is now", possibly referring to Forthencho's impending death.

During the final years of the Forerunner-Flood war circa 100,000 BCE, the Domain suffered frequent outages, often becoming inaccessible for all Forerunners. The Domain's silence following Mendicant Bias' attack on the Capital was generally believed to be a result of the Halo Array being moved across the galaxy, or the rampant AI Mendicant Bias' "exhaustion" of the Domain as it searched for answers about the Precursors and their plan for the Forerunners. However, there is evidence, uncovered by the Juridical rate, that the Domain's silence was a deliberate act on the part of the Domain itself, evidence that the Domain was in fact a conscious entity. At the close of the Flood war, the Gravemind, appearing as Forthencho, communicated with the Librarian, revealing that the Domain was actually a Precursor consciousness, and that by activating the Halo Array, they ensured that the Forerunners' history would be lost.

Despite the Gravemind's claim, something of the Domain appeared to survive the activation of the Halo Array. In 2557, during their time on Requiem, Master Chief Petty Officer John-117 and Cortana were able to partially access the Domain, learning more about the tale of the Didact and the Librarian.

Trivia

 * The Domain serves as the fictional basis for the terminals in Halo 4.
 * The Domain bears conceptual similarities to the Void Which Binds, a quantum information storage medium featured in Dan Simmon's science-fiction series The Hyperion Cantos.
 * The Domain also has resemblance to the theory of the Akashic records, a Hindu belief that all knowledge, past, present, and future, is archived on another plain of existence that only a select few can access.

List of appearances

 * Halo: Cryptum
 * Halo: Combat Evolved Anniversary
 * Terminals
 * Halo: Primordium
 * Halo 4
 * Halo: Silentium