Ralfaris was the home of the Qel'noran. Ralfaris was conquered in YE 23 and, at first, flourished within the Yamatai Star Empire. Over time, however, the Qel'noran became seen as increasingly dangerous due to their lust for power and huge military expansion.
During the Second Draconian War in YE 24, Jaaq'tah forces invaded Yamatai Space and unleashed a large-scaled planetary bombardment on Ralfaris, which killed many Qel'noran and resulted in harsh conditions on the planet's surface.
When the Qel'noran attempted to secede from the Yamatai Star Empire in YE 26, the Star Army of Yamatai destroyed Ralfaris. All that's left of the star system is that debris-filled nebula. Some Qel'noran survived, and used the Transuniversal Teleportation Drive they had to go on to other universes, one of them being Ayenee, and the Star Army and the rogue Qel'noran had scuffles in that universe for a couple years afterward.