Cyrillia was a remote world located exactly on the Outer Rim Territories and Unknown Regions, though it was considered to be on the Outer Rim side and was classified as such. The world only had a few towns scattered across the planet and one major spaceport. The Cyrillia planetary government was weak and had little authority outside the spaceport, and each town had their own leadership council.
In 11 ABY, when the Galactic Empire was defeated at Endor and the Rebel Alliance was turned into the New Republic, the Imperial Navy Major Kalkaroff, leader of the 9th Imperial Expansion Region Fleet, came to the world and using the Imperial troops, started his own criminal gang, the Imperial Conquistadors, and built his palace and headquarters on Cyrillia, and later spread his operations off world, though kept the palace and HQ on the world.
Later on, the world was home to a battle between the forces of the Fel Empire, Darth Krayt's Galactic Empire, and the Imperial Conquistadors. The Fel Empire and Conquistadors teamed up and took down the Sith's empire, and the Fel Empire in exchange moved off world and let the Conquistadors keep operating from the world.