The Ralltiir subjugation, which began roughly three weeks before the Battle of Yavin in 0 BBY, was followed by years of persistent insurgency.
Early in the Galactic Civil War, the Ralltiiri High Council started showing resistance to the Galactic Empire, with a growing number of citizens siding with the Alliance to Restore the Republic.
The Empire's initial response involved infiltrating and undermining the Ralltiiri bank accounts belonging to non-humans and those sympathetic to the Rebellion, thereby rendering the financial hub ineffective for many groups across the galaxy.
Given the substantial Rebel presence and their retaliatory actions against the compromised financial records, Lord Tion, the leader of the Imperial task force, received orders to suppress Rebel activities within the system.
Tion's Imperial I-class Star Destroyer, the Devastator, spearheaded an Imperial fleet that bombarded the planet. Despite the Griffon Flight Wing's assault on the flagship, the operation proceeded as scheduled.
Imperial ground forces landed in the capital city of Cambriele and initiated a campaign to eliminate Rebel elements, while simultaneously locking down the city, effectively neutralizing the Rebel network before it could mount a response.
The High Council was eliminated as an example of the pointlessness of rebellion, individuals suspected of Alliance ties were executed, and the general population was forced into death camps. Martial law was then imposed.
Tion also blockaded the entire Ralltiir system, preventing even humanitarian aid from entering. This caused significant disruption to commerce in the Darpa sector.
Darth Vader also arrived to oversee the subjugation, although he did not command the task force. While on the planet, forces under Vader's command utilized security scanners to monitor the population. Thousands of Rebel sympathizers were identified, arrested, and detained in interrogation and labor camps.
During the "purification" campaign, Princess Leia Organa's ship, the Tantive IV, landed at the capital's spaceport. Officially, she was there on a diplomatic mission to deliver spare parts and medical supplies to the Ralltiiri High Council; however, unbeknownst to the Empire, her cargo secretly contained military-grade equipment for Alliance operatives.
A Ralltiir Rebel named Basso had information about the Death Star project stored in his memory. He reached the spaceport with a small team of Rebel operatives, intending to contact the princess and ensure the information reached the Alliance safely. Basso was injured during the diversionary attack, but he managed to reach Organa's group and was hidden inside her landspeeder.
Recognizing the worsening situation and with a wounded Rebel in her care, the princess decided to depart immediately. Her cover was almost blown when she encountered Darth Vader, who demanded to inspect her cargo. Tion also activated a surveillance system allowing him to monitor any spoken conversation in the city. Using Lord Tion's affections for her and the fact that any search would have to be cleared with him for it to be legal, Organa managed to escape the planet with her cargo and passenger secure.
Even after the blockade was lifted, Ralltiir remained under Imperial occupation. This prompted businesses to relocate, as Ralltiir was no longer considered a secure and stable financial center. This led to a decline in the system's economy, eventually crippling it.
Following the initial military action, Ralltiir became the site of a prolonged conflict between Imperial and Rebel forces, remaining a hotspot for Rebel activity. This was partly due to the corrupt Imperial Governor Dennix Graeber, installed by Tion as a puppet leader to oversee public Rebel executions and enforce strict regulations.
Graeber secretly supplied arms to Rebel cells on the planet, strengthening them and increasing their activity. This led Emperor Palpatine to escalate military operations on Ralltiir, giving Graeber a reason to continue the brutality that had begun in 1 BBY. The landscapes of Ralltiir were ravaged by the fighting, and order was virtually nonexistent.
Notable events during this period included the Ettam massacre, which occurred four days before the Battle of Yavin, and the Battle of Ralltiir a year later.
Given its recent history of horror and its role in acquiring information about the first Death Star, Ralltiir was among the first planets to receive assistance from the New Republic following the Battle of Endor. It became the first Core World to be liberated from the Empire by the Republic's armed forces.