The Cularin system was on the Mid Rim-Expansion Region border and was located just off the Corellian Trade Spine, in between Kalarba and Aridus. It was a seven-planet binary star system that contained the planets of Cularin and Almas. It became a five-planet system when the planet Oblis was destroyed by the power of the Darkstaff. This destruction also knocked Dorumaa from its orbit to eventually become a moon of Almas.
The Cularin system was visited by Darth Rivan during the New Sith Wars, leading to the creation of the Almas Sith fortress. The Jedi eventually drove the Sith Lord out of the system, log the system's name in a Republic database, and Cularin was forgotten.
Though the Cularin system was in a well explored sector of space, and was close to a major hyperspace route, it remained undiscovered due to the gravity anomalies there. The dense cores of three of the planets created very large gravity reflections, which sometimes overlapped. Also, the cloud of comets in the seventh orbit created its own astrogation difficulties. It was best to revert from hyperspace outside of the comet cloud and make the calculations for entering the system after getting current readings on the behavior of the comets. Even this was not considered safe by most traders, who chose instead to come into the system by sublight, passing on the increased cost of operation to their customers through higher prices.
A scout named Reidi Artom rediscovered the Cularin system in 232 BBY, and conducted the first real exploration of the system. Others followed her, and settlements were built on most of the system's bodies. Due to the relative isolation of the system, crime rates were high: The local asteroid belt became a refuge for pirates and later for crimelords such as Riboga the Hutt and his successor Nirama.
The Cularin system joined the Republic around 32 BBY, and immediately asked for military protection against the pirates; however, the Thaereian military forces proved inefficient in ending the pirate attacks, and the Thaereian military proved to only blockade the system.
Shortly thereafter, the entire system disappeared from the galaxy for almost a decade, reappearing during the Clone Wars. The inhabitants of the system experienced no passage of time during this disappearance. Towards the end of the Clone Wars, Senator Lavina Wren declared Cularin to be a sovereign system, aligned neither with the Republic nor the Confederacy of Independent Systems.