Delphian Empire
From Battlestar Wiki, the free, open content Battlestar Galactica encyclopedia and episode guide
Gamoray was the capital planet of the Delphian Empire, conquered and destroyed by the Cylons sometime before the destruction of the Twelve Colonies; its extent is unknown, as is whether it was peopled by humans or aliens. Clearly known to the Colonies, but obviously not in regular contact with them (The Living Legend, Part I).