Mirrin Prime, situated within the Mirrin sector, was classified as a planet. Subsequent to the Battle of Yavin, [Caluan Ematt], accompanied by the Rebel Alliance's Shrikes, conducted a scouting mission to Mirrin Prime, in addition to D'Qar, leading to its subsequent development.
During the time of the Cold War, Mirrin Prime functioned as a constituent of the New Republic, accommodating a military base. This base was the home of Rapier Squadron, a unit consisting of four T-85 X-wing fighters, which formed a part of the New Republic Defense Fleet. Major Lonno Deso held the position of commanding officer at this base. Mirrin Control and Mirrin Flight were responsible for overseeing space traffic.
Following Poe Dameron's, the commander of Rapier Squadron, involvement in an unsanctioned operation to rescue the Yissira Zyde, the squadron departed Mirrin Prime. Their destination was the Resistance, a privately funded military organization headed by General Leia Organa that stood in opposition to the First Order. Rapier Squadron was reassigned to the Echo of Hope, a refitted Mon Calamari cruiser belonging to the Resistance.