During the Galactic Civil War, the Battle of Bespin occurred around the same time as the Battle of Endor.
In 3 ABY, the Galactic Empire took control of Bespin, the gas giant famous for its Cloud City and its tibanna gas mines. While the Empire seized the city and its mining operations, they only stationed a small garrison there. Despite the Empire's tight grip, the Rebel Alliance launched some small raids, including at least one that took place in 4 ABY, before the Battle of Endor.
Cloud City became the target of an assault by the Rebel Alliance. This confrontation unfolded both in the skies above Bespin and on the floating settlements. The fighting began in the capital and spread across the various gas refineries as the Rebels advanced.
On the ground, Rebel soldiers successfully seized the primary carbon-freezing chamber and established secure command posts in the surrounding area. Under the pressure of the Rebel offensive, Imperial stormtroopers and snipers retreated.
Next, the SpecForce shifted their focus to capturing the primary mining platform under Imperial control.
After landing, the Rebel forces took control of the gas extractor and pushed the Imperials to the opposite side of the platform. The Rebel forces advanced, seizing the Imperial docks and landing platforms, effectively trapping the Imperials within the main command center. Y-wings carried out bombing runs on the building, while X-wings eliminated Imperial starfighters before they could take off, which caused the enemy forces to decrease. SpecForce teams then moved into the command building and took control of the mining platform.
Despite the attack on the Imperial garrison, the liberation of the city did not occur until after the Battle of Endor in 4 ABY.
This battle was featured in the Star Wars: Battlefront video game from 2004, across two Galactic Civil War missions in a row. However, Leland Chee, the Keeper of the Lucasfilm Holocron continuity database, has stated that the storyline is considered S-canon. In both missions, the player fights on the side of the Rebellion. In the second mission, both players and the computer have the ability to capture neutral Cloud Cars. Although the game's strategy guide provides maps of the battle locations, it lacks information about the Historical Campaign.