Battle of Turkana
during the early years of the Galactic Civil War, the Empire tried to destroy the hopes of the Alliance by eliminating a fleet which had been massing near Turkana. An Imperial Star Destroyer ambushed the main fleet of Alliance Mon Calamari cruisers in orbit around the planet, taking the Alliance forces by surprise. The Alliance, however, successfully repelled the ambush due to the Imperial knowledge of Admiral Ackabr and the introduction of the X-Wing starfighter.