Final Defense at Raynet
The Final defense at Raynet was a last-ditch effort near the end of the Ur-Quan Slave War to stop the Ur-Quan fleet at the Raynet constellation. It is unclear when exactly this battle occurred and which races of the Alliance were involved. It is known that the Syreen Space Patrol was involved — Talana states that her sister, Diani was killed in the battle.
As Talana is the only one that mentions this battle, it may be that only the Syreen fought in this battle. In this case, this final defense would have been the Syreen's last stand before being defeated by the Hierarchy of Battle Thralls, and would have occurred after Earth had been conquered. Another possibility is that this was the final, unsuccessful attempt by the bulk of the Alliance forces to maintain the Coreward Front after the Hierarchy had broken through the Indi-Mira line, ultimately pushing "beyond Raynet." This would also place the battle at the end of the War, but prior to the costly fight to hold Rigel and the subjugation of the Chenjesu and Mmrnmhrm.
Possibly, the Syreen were the only Alliance race that participated in the battle, but it happened before the battle at Rigel.