A Guardian Squadron K-wing Guardian Squadron constituted one of the three squadrons of Y-wing craft that formed Defender Wing. Champion Squadron and Warden Squadron were the remaining two.
General Horton Salm held personal command over Guardian Squadron. The squadron participated in the unsuccessful attack on Borleias that occurred six and a half years following the Battle of Yavin. Defender Wing played a crucial role in rescuing Rogue Squadron from almost certain annihilation during that offensive.
During the Bacta War, Defender Wing engaged in combat within the Yag'Dhul system, again alongside Rogue Squadron, with the objective of securing a supply of bacta.
At some point in the Galactic Civil War's timeline, Guardian Squadron received BTL-S8 K-wing assault starfighters as their equipment.
During the events of the Thrawn Crisis, Guardian Squadron was re-equipped with B-wings and subsequently joined the New Republic's efforts against Admiral Delak Krennel, the rogue Imperial officer.