Nolan Byrne

Staff Sergeant Nolan Byrne is an UNSC Marine, a Team Leader on ORION Project, and a possible SPARTAN-I. He was in Operation: TREBUCHET with Avery J. Johnson, until he was severely injured from an insurrectionist bomb. Byrne was then reassigned to the planet Harvest to train a local militia with Avery J. Johnson.

Career in UNSC Marine Corps and NAVSPECWAR
Byrne participated in Operation: TREBUCHET in 2524 leading Bravo Squad of a platoon of NAVSPECWAR marines alongside Staff Sergeant Avery J. Johnson. Their squads used Hornets to conduct air assaults on multiple targets in efforts to eliminate Rebel bomb making factories. However, when a rebel (armed with a bomb) was cornered in a Jim Dandy restaurant, Byrne told Johnson to fire an M99 Special Application Scoped Rifle, (A.K.A gauss-rifle), at an Insurrectionist holding a child hostage. Johnson did not have a clear shot at the rebel, which lead to a civilian (a man trying to rescue his son) tackling the female rebel, who then detonated her explosives, which destroyed the Jim Dandy restaurant, along with many of the Marines in Byrne's squad and thirty eight civilians.

Battle of Harvest
After recovering from his injuries, Byrne was re-assigned along with Johnson to train the Colonial Militia on Harvest, but their actual mission was to create an covert anti-insurgency unit, and to lay an ambush on insurgent forces suspected in the disappearances of DCS freighters around Harvest. However, He and Johnson fought four Jackals in the first battle between the UNSC and Covenant,on board the human freighter called This End Up, and they successfully defeated them. Byrne and Johnson (with the rest of the militia of harvest) were also present at the initial negotiations between the Brutes and the Humans. They also fought Tartarus, Maccabeus and several Grunts. One militia soldier was torn apart by a Grunt, which sparked the firefight. As the conflict heated up, Byrne continued to defend the planet from Covenant hostiles and he received multiple injuries in the conflict. He was fortunate enough to live through the battle, and evacuated with Johnson, Jilan al-Cygni, and the rest of the Colonial Militia in a Pod heading from the Tiara. How Byrne participated more in the Human-Covenant War is currently unknown.

Trivia

 * Byrne lost a tooth after a prolonged scuffle with Sergeant Johnson.
 * In Halo: Contact Harvest, Byrne's call sign is Creeper.
 * He is most likely HEV Orbital Drop qualified given the fact he has the same training as Sergeant Johnson while in NAVSPECWAR.
 * It is possible that Nolan Byrne was a Spartan-I alongside fellow Sergeant Johnson. This is because in the fight they have in the beginning of the book, Byrne said: "They taught BOTH of us to be killers". But this could just be a reference to their NAVSPECWAR training or even their basic training.
 * Byrne is the only character mentioned in the Halo series who is Irish, save for the Marine who appeared in the Halo E3 2000 Trailer, which isn't canonical.