From Halopedia, the Halo wiki
- January: Eridanus II is claimed by the Secessionist Union.
- The Sundered Legion is defeated on Meridian after the Siege of Athea.
- December 12: The insurrectionist philosopher, Yera Sabinus, writes "No prison can hold a free mind" on toilet paper with her blood while incarcerated at Colonial Administration Authority Detention Center 3063-OM-Y.
- The UNSC takes control of the station UNSC Hopeful and adds fusion reactors and a Shaw-Fujikawa Translight Engine, turning the Hopeful into the largest mobile battlefield hospital in history.
- After only two years of service, the Valiant-class super-heavy cruisers, including the UNSC Valiant, are temporarily scrapped by the UNSC Navy.