Tensions and rivalry already existed between the Sangheili and Jiralhanae, long before the Human-Covenant war. However, it was the Changing of the Guard that eventually lead to actual battles between the two species. This event helped split the Covenant Empire and ultimately end the Great war.
Fighting continued directly after the Human-Covenant war. Initially the Jiralhanae were winning due to the remaining Prophets providing organization and resources, but the tables turned when they went into hiding. The Jiralhanae started fighting against each other giving the Sangheili the advantage.
The Covenant had settled the Jiralhanae on resource-rich worlds. However, since the Jiralhanae are "decades behind the other Covenant races technologically," they had to steal supplies from the Sangheili because they did not have the ability to mine and use the resources they already possessed. Since the Jiralhanae had little communication within their kind, these attacks were highly disorganised.
- “Guardians of the righteous! Silence the blasphemers!”— Jul 'Mdama's Covenant soldier
- Main article: Battle of Ealen IV
In 2558, both sides wanted to reach some sort of agreement. Since the Jiralhanae forces were distrustful of the Sangheili, they agreed on Thel 'Vadam's proposition to have humans mediate their discussion. The UNSC and Swords of Sanghelios realised that pacifying the Jiralhanae forces were in the best interest of everyone, so it was humanity's job to make that clear to the Jiralhanae.
In order to try and establish an agreement, the Swords of Sanghelios requested several high-ranking humans of the UNSC to sit in their discussions and mediate negotiations on the neutral planet of Ealen IV. On part of the humans, Admiral Terrence Hood and Captain Thomas Lasky were chosen as negotiators, the Sangheili were represented by Kaidon Thel 'Vadam and the Jiralhanae by the Elder Chieftain Lydus. They agreed also that each faction should have a strong military force, Spartans, Sangheili Commanders and Jiralhanae Captains alike.
The negotiations were soon attacked by Banshees from Vata Gajat's Mercenary Group, killing multiple Sangheili Commandos. The Jiralhanae Lydus assumed Thel 'Vadam was behind the attack, but Thel denied this accusation and started fighting the Remnant forces as well. Despite surviving the attack, no agreement between the parties was reached.
- ↑ Halo: Evolutions - The Return
- ↑ Halo: Fractures - Shadow of Intent
- ↑ 3.0 3.1 3.2 3.3 Halo: Evolutions: The Return - It was a terrible war. The Prophets provided the Jiralhanae with powerful new weapons, hoping that they would in turn defend their Prophets against our wrath. But when the Prophets went into hiding, the lack of leadership allowed the Jiralhanae to return to their savage nature and they soon began to fight against each other. This lack of solidarity made them much easier prey. Some of my fellow commanders continue that fight even now.
- ↑ 4.0 4.1 Halo: Escalation Issue #1 - page 14
- ↑ 5.0 5.1 5.2 Halo: Escalation Issue #1 - page 15
- ↑ Halo: Escalation Issue #1 - page 20
- ↑ Halo: Escalation Issue #1 - page 22 - 24