Illyrian

The Illyrians are a technologically-advanced species in the Milky Way galaxy who are infamous for their role in the creation of the Silentium—a race of hyper-intelligent robots that once ravaged the galaxy prior to humanity's introduction into the Old Republic. The Silentium drove the Illyrians off of their homeworld of Rannoch, and the species have since lived in wandering fleets known unofficially as the Migrant Fleet.

Pre-Old Republic
Approximately 100,000 years before the foundation of the Imperium in .M11 AD, the Illyrians maintained a vast, interstellar domain that stretched the entire width of the galaxy. Their planet, Rannoch, possessed a treasure trove of Precursor artefacts, which allowed them to advance lightyears ahead of the other races that roamed the galaxy. They enslaved many of the races they came across and forced them to create the Confederation's mighty fleets.

The downfall of the Illyrian Confederation is a topic that has baffled historians for millennia. Their empire was rich with resources, its people rejoiced as they drown themselves in the wealth of their enemies; yet, they fell. However, when one examines the ancient hulls of the Illyrian ships, one can see the charred marks of laser fire on its adamantium hulls. Perhaps they were attacked by someone? Whatever the reason, it is safe to assume that their mysterious assailant did not stand against the test of time. But as their offenders vanished into the void, they left behind the great Illyrian people eternally scarred. Their only bastion was Rannoch—their homeworld whose atmosphere had begun to show signs of degradation after centuries of pollution. Some retreated into space, forming some of the first Migrant Fleets in galactic history, but most Illyrians chose to serve the rest of their dying days in exile. Thus, for thousands of years, they waited quietly in the dark, hoping one day to reclaim their position in the stars. As fact turned to legend and legend into myth, the glorious history of the Illyrian race was lost to the void and their people regressed to a state where they had to relearn everything once again.

Contact with the Old Republic
Their exile on Ranchor was one fueled by self-loathing and anxiety. They were ashamed of their past actions and so sought to amend them by reorganising their society into a pacifist society—one that prioritised the wellbeing of others for the 'greater good'. Thus, when word began to spread of a utopian-esque society on the fringe of Republican space, a great amount of effort was poured into indoctrinating Illyrian society into the galactic fold.