Great Schism

Concurrent:	Human-Covenant War
Next:	Sangheili-Jiralhanae war
Great Schism
Date:	November 3, 2552–December 11, 2552 (First Age of Retribution)
Location:	Orion Arm, Milky Way Galaxy
Outcome:	Sangheili victory Dissolution of the Covenant San'Shyuum reduced to an endangered species Ongoing conflict between the Sangheili and the Jiralhanae
Details Belligerents Covenant Covenant separatists Commanders High Prophet of Truth† High Prophet of Mercy† Prophet of Exquisite Devotion† Chieftain Tartarus† Chieftain Gargantum Chieftain Avitus Captain Melchus Arbiter Thel 'Vadam Shipmaster Rtas 'Vadum Unidentified Sangheili Shipmaster Fleet Master Voro Nar 'Mantakree† Imperial Admiral Xytan 'Jar Wattinree† Blademaster Vul 'Soran Fleetmaster Rojka 'Kasaan Strength Covenant military Prophet of Truth's fleet Jiralhanae-led High Charity defense fleet Fleet of Furious Redemption San'Shyuum Jiralhanae Yanme'e Kig-Yar Few Unggoy Few Mgalekgolo Huragok (unwillingly) Fleet of Retribution Fleet of Righteous Vigilance Fleet of Recalcitrant Ire Joyous Exultation Covenant Combined Fleet of Righteous Purpose Sangheili-led Second Fleet of Homogeneous Clarity Sangheili Most of the Unggoy Most of the Mgalekgolo Huragok Casualties Most San'Shyuum (reduced to an endangered species) High Prophet of Mercy High Prophet of Truth Many Jiralhanae Chieftain of the Jiralhanae Tartarus Many Yanme'e Many Kig-Yar Some Unggoy Few Mgalekgolo Many Sangheili Fleet Master Voro Nar 'Mantakree Imperial Admiral Xytan 'Jar Wattinree Some Unggoy Some Mgalekgolo

"By the Prophets… what have these Brutes done? They have shed our brothers' blood… and for that, they must die!"

— Sangheili on Installation 05.

The Great Schism, also known as the Covenant Schism, was a major civil war between the forces loyal to the Covenant (led by the San'Shyuum and the Jiralhanae) against the Covenant separatists (the Sangheili and their followers), which split apart on November 3, 2552. The High Prophet of Truth ordered the extermination of the entire Sangheili species, forcing them out of the Covenant. Battles during the Schism took place all throughout Covenant space, most prominently on High Charity, the heart of the alien empire. The Flood additionally played a tertiary role, when they took over the holy city in an effort to assimilate the other warring factions. The deciding battles were fought between the Sangheili Fleet of Retribution allied with the UNSC against the High Prophet of Truth and his remnants of the Covenant on the Ark. The Schism marked both the end of the Covenant and the partition of its client species for a thousand years. For the UNSC, it served as a major turning point that led to the end of the war after their disastrous defeat on Reach.

The conflict went down in Sangheili history as the Great Betrayal, its deep wounds continuing to stir animosity between their kind and the Jiralhanae for years to come.

Background

Thel 'Vadamee: "We are strong, Kig-Yar. That is why we sit at the right hand of the Prophets."

Reth: "One day that shall pass."

— Conversation between Reth and Thel 'Vadamee in 2535