Shortly before the Rebellion the Knight's Legions engaged a Hiver company and a force of Ithklur and brought them to Reavers' Deep (Outpost, the Knight's Legions' home world at that time) to train the Legions' forces in some of their techniques.
The Rebellion trapped them in Reavers' Deep so they joined forces with the Knight's Legions for a while. Then came virus. During 1132-1133 the Knight's Legions fought a running battle with a vampire fleet out of the Daibei sector.
The vampire fleet smashed the Legion's facilities at Outpost and chased the remaining fleet, along with the Ithklur forces, down the length of the Drexilthar Main. The Legions' forces made a last stand at Lanixohn with other Legions' forces it had collected in it's retreat. After a pitched battle, in which the Hiver company ship was destroyed, the vampire fleet was defeated. The Ithklur force survived as they had been dispatched with other Legions' forces to protect ground facilities.
Heavily damaged, the commanders of the fleet obeyed the last command of their Supreme Commander;
"This is a battle we cannot win now. Go to a habitable world and hide your technology. Go to ground, fight and defend those who you protect. We will find a means to defeat this new threat and we will rise again. Survive today and we will fight tomorrow."