2541

March

 * March 12: Kojo "Romeo" Agu enlists in the UNSC Marine Corps, at the minimum age of 16.

August

 * August 24: SPARTAN-III Beta Company undergoes one of a series of exercises intended to select candidates for further training. Using unconventional tactics, the Spartans of Team Foxtrot appropriate M202 XP machine guns along with weapons and armor from several waves of their instructors before being eventually ordered to stand down by Lieutenant Ambrose and CPO Mendez.

Unknown

 * The game Hyperforce is enjoyed by civilian children.
 * Rion Forge's grandfather dies of Boren's Syndrome.
 * The UEG colony of Barugi is quarantined following a deadly outbreak of asteroidea merozoite three years prior. A series of thermonuclear Hornet mines are deployed around the planet to prevent the spread of the disease to other colonies. All UEG and UNSC vessels are instructed not to approach the planet.