Historic Battles er navnet på den første rigtige udvidelse til Halo Wars. Der er tale om fire nye baner, der er tilpasset 1 mod 1, 2 mod 2 og 3 mod 3 kampe - og så er der endda 100 nye Achievement-points at jagte. Historic Battles kommer til at koste 800 Microsoft points og den lanceres d. 21. juli.
De fire nye Achievements
• Tour Coming Through: Hot drop 50 squads to your Covenant Leader in a single game on Memorial Basin (30 points)
• Never Leave a Man Behind: Finish a game with 5000 net resources contributed to your teammates on Memorial Basin (15 points)
• Drain Cleaner: Kill 20 enemy squads with a continuous Covenant Leader Power on Memorial Basin (30 points)
• Killjoy: Disrupt 5 active Leader Powers in a single game on Blood River (25 points)


<bild>Memorial Basin (2v2 Map): The high ground in the middle offers good cover for infantry, while the generally open terrain transforms organized battle plans into bloodbaths.</bild>
<bild>Glacial Ravine (3v3 Map): A snow-topped mountain range forms a natural barrier that cuts this region in half. Control of the two energy walls at the narrow central pass often determines the outcome of the battle, though clever use of the Sentinel Factories may play a role as well.</bild>