Metarch-class ancilla

Mendicant Bias, the most capable Metarch ever created by the Forerunners.

Metarch-class ancilla, or more simply Metarchs, were a class of hyper-advanced ancillas created by the Forerunners to serve the Ecumene Council, and served to administer significant portions of the Ecumene's day-to-day operations. Their exclusive nature meant that by law, only five such examples were ever in existence at any given time.

As part of their operation, a given Metarch-class ancilla governed an enormous network of lesser ancilla and monitors known as a Metarchy. These networks and their commanding Metarchs were tasked with the most large and complicated construction projects and were tightly constrained by law.

A sub-metarch was a class of ancilla below a metarch. These AIs were commonly assigned to flotillas of several vessels such as Raptors, their intelligence distributed among the ships under their control. While they would only respond to the flotilla's commander, this could be bypassed with the proper verbal override codes. These codes were incredibly complex, consisting of hundreds of random words and numbers.

During the Forerunner-Flood war, the Forerunners activated a new ancilla known as Mendicant Bias. At the time of its creation, Mendicant Bias was considered to be the most advanced Metarch ever created, so much so that it existed in a class of its own - the Contender-class artificial intelligence. Ultimately, Mendicant Bias turned to a servant of the Flood during the war, resulting in all Metarch-level ancillas undergoing programming by the Forerunners to remove all traces of Mendicant Bias' corrupting influence from their systems. Flood Keyminds were considered more than a match for a Metarch's intellect.

List of appearances

• Halo 3
  • Terminals (First appearance)
• Halo: Contact Harvest
• Halo Legends
  • Origins
• Halo: Cryptum
• Halo: Primordium
• Halo: Silentium
• Rebirth
• Halo: Escalation
• Halo Mythos
• Halo: Fractures
  • Promises to Keep (Mentioned only)