The onset of the Great Schism during the Battle of Installation 05 on November 3rd, 2552, pitted Jiralhanae-commanded ships against Sangheili ships.
SUMMARY
The Great Schism was a conflict between the forces loyal to the Covenant, led mostly by the Jiralhanae, and the Sangheili, beginning on November 3rd, 2552 and continuing off and on until the Rule of the Created in 2558. Although the Sangheili had been the right-hand of the the San'Shyuum since the formation of the Covenant, the Prophet of Truth, in an attempt to consolidate and strengthen his power, empowered the Jiralhanae to take all the leadership roles within the Covenant from the Sangheili. The move was considered a coup by most of the Sangheili in the Covenant, and led to a split of forces between those loyal to the Covenant, headed by the Prophet or Truth, and the Sangheili, led by the Arbiter Thel 'Vadam. As the Great Schism occurred during the Battle for Earth, the Arbiter's forces ended up allying with the UNSC and ultimately drove back the Covenant and killed Truth. While the death of Truth and the other two Hierarchs Mercy and Regret severely weakened the Covenant and put an end to the Human-Covenant War, it also created a power vacuum that resulted in the continuing fighting between Arbiter loyalists and former Covenant powers. The Great Schism is widely attributed to allowing the UNSC and humanity to win the war.
RELATED MEDIA
These events are depicted in the video games Halo 2, which was the subject of several Mission Debrief episodes in fall to winter 2018, and Halo 3, which was the subject of several Mission Debrief episodes in spring to summer 2019.
