Happy birthday to Warmaster Atriox!
Today is his -484th birthday!
Atriox was born into the Covenant, serving as a member of the Bloodstars. In the later years of the Human-Covenant war, his clan was increasingly used as cannon fodder to break the front lines, seeding a resentment towards the Covenant and its leadership.
Atriox repeatedly survived these encounters, an outcome his superiors did not expect. Over time, he developed a legendary status among his people. Though Atriox was willing to fight the campaign against the humans, he did not share in the Covenant faith. This began to draw concern, and eventually the Prophet of Truth ordered him to be quietly executed to avoid martyrdom.
Atriox was set up to be followed at his next deployment. During a battle, he aired his frustrations to a terrified human marine, denouncing the Covenant faith and the war before killing him. His beliefs exposed, the Jiralhanae that followed him accused him of blasphemy and challenged him. They fought, and Atriox killed him, giving his superiors an excuse to have him executed for killing his own kind.
Rather than accept his execution, he killed his would-be executioner, emboldening the Jiralhanae around him to rebel against the Covenant, forming the Banished.
In the years that followed, the Banished engaged in several raids against the Covenant and the UNSC. When the Covenant fell, they took advantage of the power vacuum, seizing weapons, vehicles, and recruiting widely to all species.
During the Created conflict, Atriox seized yet another opportunity travel to the Ark, intent on gaining the ability to construct Halo rings. His plans were intercepted by a UNSC presence there. While he was there, he learned of the Xalanyn, hidden on Zeta Halo. The battle raged for months, with Atriox no closer to success. In an effort to turn the tide, he sent brothers Voridus and Pavium to High Charity to salvage. However, this lead to a Flood outbreak, and Atriox was forced to leave the Ark to address this more pressing matter.
Rather than return to the Ark as expected, Atriox left for Zeta Halo to seek the Xalanyn. He encountered resistance from Cortana and the Created, which lead to the destruction of Dosiac, the Jiralhanae homeworld. As the battle on Zeta Halo raged, he arranged for an ambush against the UNSC Infinity. He personally attended the battle, targeting and besting--but not killing--Master Chief.
He then turned his attention back to Cortana, who, having realized the havoc she caused, blew up part of the ring, sacrificing herself to stop Atriox, who was then presumed dead. However, it appears that he was only grievously injured, and survived to be an enduring thorn in Master Chief's side.
In canon (~2560), he is turning 50!