The Five Day War was a conflict from when the Empire and the Alliance clashed in the Mobius V system. Most of the Imperial fleet was destroyed because of the Alliance fleet's size. The Alliance did not know that the "Imperial fleet" was actually a fleet of Zi'tcha, which had taken over the fleet. Secretly, the Ants wanted confict between the two factions.
The Battle of Krytes
The Alliance retaliated by attacking the nearby fleet in the neabry system. Both forces were equally strong in space and on land, but after five days of fighting both sides finally realized what had happened.
The system, once controlled by the Empire and Alliance, was destroyed by the Ants. However, after the factions united and drove out their foe, the factions reclaimed the system and got back their planets.