Covenant separatists Explanation Halo

“There was honor in our Covenant once, and there shall be again!”
— Thel 'Vadam

Covenant separatists is the name given to the forces who broke away from the Covenant during the Great Schism, composed of all the ejected Sangheili, as well as others who allied with them. When the Great Schism broke out on November 3, 2552, the entirety of the Sangheili species were forced out of the Covenant. The High Prophet of Truth had ordered the Covenant military, now led by the Jiralhanae, to massacre the Sangheili. This caused a massive civil war to erupt across Covenant-controlled space.

Though only the Sangheili were forced out, many of their former allies sided with them instead of siding with the Jiralhanae and the San'Shyuum. Many Unggoy and Mgalekgolo and even one prophet, Zo Resken, joined the Sangheili-led Covenant separatists.

Origins

The Covenant separatists were formed as a result of the Great Schism. Following a poorly-planned mission to Earth and a hasty retreat to Installation 05, the Prophet of Regret was assassinated by John-117. Using Regret's death as leverage, the Prophet of Truth set in action his plan to have the Jiralhanae usurp the Sangheili as military leaders of the Covenant. First Truth acted slowly, replacing his protection detail with Jiralhanae but soon, all-out war had broken out, following Truth's order that the Jiralhanae should rise up and kill the Sangheili.

In response to the betrayal, the Sangheili formed an organization colloquially known as the Covenant separatists, supported by both many Unggoy and Mgalekgolo (though many of the latter species would return to the Loyalists' side soon after). During the early hours of the conflict, the movement lacked leadership, but several leaders would soon emerge. The Arbiter Thel 'Vadam rescued several of the few surviving Sangheili High Councilors from Jiralhanae captivity and met up with Shipmaster Rtas 'Vadumee on Installation 05, forming the Fleet of Retribution. Concurrently, Imperial Admiral Xytan 'Jar Wattinree took command of a large fleet of surviving Sangheili ships, including most of the Combined Fleet of Righteous Purpose.

All Sangheili groups worked together to destroy the Covenant Loyalists led by the Prophet of Truth and Jiralhanae, although only the Fleet of Retribution division of Sangheili would extend their allegiance to the UNSC.

Joyous Exultation

Xytan 'Jar Wattinree was unaware of the alliance forged by the Arbiter and so he continued to treat humans as enemies. Unfortunately for him, however, he and his fleet were soon destroyed by a NOVA Bomb, leaving Thel 'Vadamee as the figurehead of the rebellion. Though not easily persuaded, the Arbiter was able to convince the rest of the Sangheili to join with Humanity. While the two factions experienced some initial friction, they learned to work with one another for mutual survival.

Sangheili-Human alliance

Within the Covenant separatists, only the Fleet of Retribution division allied with humanity during the final battles of the war.

The shaky-to-steady alliance between the Fleet of Retribution and their former foes, the Humans, was forged entirely out of necessity. The UNSC forces were on the defensive, and they had two common enemies that wished for their extinction: the Covenant and the Flood. The alliance of circumstance was forged in the control room of Delta Halo, when Johnson and the Arbiter were coerced to unite in order to prevent Tartarus activating Installation 05.

The devastated UNSC Fleet in Earth's space gladly accepted the help of the superior Fleet of Retribution warships. The Sangheili understanding of Covenant combat equipment and tactics proved invaluable in the Battle of Installation 00. The battle's recurring heroes, Thel 'Vadam and John-117, fought alongside one another many times in the desperate and long conflict.

With Truth dead, High Charity destroyed, and the Ark essentially lost due to the firing of the reborn Installation 08, it is unknown what exactly the remaining Loyalist forces did. The Arbiter's presence at memorial services for John-117 indicated that in the wake of victory, Fleet of Retribution and Human forces remained friendly to one another, as they both had made tremendous sacrifices in order to stop Truth and the Loyalist forces.

Post-war

Main article: Swords of Sanghelios
After the Covenant separatists were victorious in destroying the Covenant that had betrayed them, the ejected Sangheili split off into several remnant factions. The Sangheili who were in the Fleet of Retribution would later form a faction known as the Swords of Sanghelios, which would become the official government of Sanghelios.