The Origins of the Swarm.

Aeons ago; the Prothen, Firstborn of Adru, spread across the Dagen Region and taught the tribal Notross the arts of war.  For a great blight was burning a path of destruction across the stars.  The blight was the Swarm.
The Swarm spread from Zarsus and burned a path of destruction to Dagen.  The Swarm encountered the Prothen and Notross, who fought off the insectoid monsters.  The Overmind, the supreme will of the Swarm, inflicted the Prothen with a terrible virus, that ate flesh and bone away to nothing.  Kalssenon, Hierarch Executor of the Prothen, devised a way, using psionics and technology, to put cybernetic implants in the remaining Prothen and Prothen eggs.  The sparse amount of Prothen withdrew to their ancestral homeworld of Arung Uni.  The Notross, after the devastating war with the Swarm, reverted back to their tribal ways, losing all technology and communication with the Prothen.  After centuries of primitive tribalism, the Prothen returned the knowledge of warp drives and ordered law to the Notross.  The wisest Prothen seers foretold that a fourth species would come from a far sector of the Dagan Region, and that their coming would herald the second coming and destruction of the Swarm.  Notross refused to accept that an outsider species could save the Prothen and Notross.  The two species fell out of communion with each other.  After the centuries, the Swarm turned to myth among the Notross, an alien invasion long ago defeated, no need to dwell on the past.  The Prothen on Arung Uni saw the signs: the return of Zarsus Prime in the night sky and the shadowing over of all adjacent stars.  The Swarm was rising yet again.