Gamma Group was a group within the fleet of the Rebel Alliance under the command of General Hera Syndulla. The group was present at the Mako-Ta Space Docks, where it and other sub-groups were to disperse from the rest of the fleet until it was required to fight against the Galactic Empire. It received at least one of the refitted Mon Calamari Star Cruisers, the Geist，which was given to General Hera Syndulla as her flagship.
As the groups were ready to launch into hyperspace, a fault occurred resulting in the ships being unable to launch, caused by Queen Trios' betrayal. Shortly after the launch failure, Death Squadron under the command of Darth Vader arrived. The Geist was one of the first Rebel cruisers to come online. Syndulla ordered her crew to give the Empire hell, to give the rest of the rebel fleet time to restore their systems. Having lost at least half of their cruisers, the rest of the fleet made the hyperspace jump, including the Geist.