The Reunification War
Military action
2577
2597
The Reunification War, some times referred to as "Wars of Reunification", was the first interstellar war backed by the entire Star League. The war was fought in tandem by the forces of the Star League Defense Force and the armies of the Draconis Combine, the Federated Suns, the Free Worlds League, and the Lyran Commonwealth. Each of the four major Periphery realms was conquered by the end of the conflict.
https://www.sarna.net/wiki/Reunification_War