Heavy cruisers were the first real step of escalation in ship sizes during the First Interstellar War. The Khanate of Orion Navy had fielded light cruisers since before the war, but the Terran deployment of larger heavy cruisers in 2207 started an escalation in ship sizes that continued for the rest of the war with the Orion's Delgor-class seeing service later that year. Although quickly dwarfed, heavy cruisers remained an important part of the frontline fleets for years. By the Third Interstellar War, with the arrival of strikefighters, heavy cruisers declined in importance and were less often seen in frontline combat.
The Oregon-class was the backbone of the Terran Federation Navy in ISW1, with excellent speed and formidable shields and armour while the mounted a balanced mix of missile launchers, force beams and primary beams. The Oregon-class formed the basis for the later Yugoslavia-class, and surviving units of both classes were later upgraded to the Greece-class after the Second Interstellar War.