From Halopedia, the Halo wiki
- June 1: Covenant forces begin to swarm into the Inner Colonies. For several years the war falls into a pattern: the UNSC wins isolated battles, typically during ground operations, but at a horrible cost. In space, the humans are losing at a precipitous rate, and one by one, the Inner Colonies fall.
- Hayabusa Powered Assault Armor is developed by Facility RKD and accepted by the UNSC Ordnance Committee late in this year.
- Kat-B320's mother dies of cancer.
- An insurrection on Mamore, and several conflicts in the Bonanza asteroid belt and the Far-gone colony platforms are fought either late in this year or 2537. SPARTAN-III Alpha Company distinguishes themselves in these engagements.