ISW-4, or Inter-stellar War four, was the titanic clash between the Arachnids and the Grand Alliance. It was the largest war fought in known space. The death toll was enourmous, such as the 4 billion dead civilians of the Kliean Atrocity. Starting around 2360, it ended ten years later. Coming out of the war, the Arachnids were all but extinct and the Terran Federation was the greatest power in known space. It had a new ally, the Star Union, the largest navy in known space. supported by it's huge complement of Monitors, and the best warfighting technology in the grand alliance.