- Capellan Justine's Grenadiers successfully repulse Marik Militia raid against Kwamashu.
- Wynn's Roost, capital of the Traders Domain province of the Outworlds Alliance, is raided by forces from Ammon, another Outworlds Alliance world.
- Early 2820: First batch of 100 Clan artificially gestated children implanted in Iron Wombs.
- September: Surviving forty children from the first batch of "Tank-Borne" emerge from Iron Wombs.
- Primus Conrad Toyama visits Succession State leaders to explain ComStar's new religious direction and the need to raise HPG transmission rates.
- Peace talks between Lyran Commonwealth and Free Worlds League held on Bella I.
- Starving population of Chertan depose the planet's noble ruler.
- Ross Steiner dies.
- Capellan Confederation forces destroy Kong Interstellar's ground based production lines on Connaught, ending production of the Black Knight BattleMech.
- Harrow-Deerfield Heavy Industrial Works's production lines on Tamar are destroyed.
- Clans develop the Medusa Whip.
- Clan scientists begin to refine the Clan-grade Streak SRM-4.
- Clan scientists begin to refine the Clan-grade Streak SRM-6.
- Clan scientists start to produce LB-X Autocannons in all calibers.