Throughout its operational history, the 5th tended toward assignments that saw them stationed on outposts that had been established on planets in the Outer Rim Territories, close to the frontiers of the Galactic Republic. This led to their participation in the defense of Bad Alshir, along with the 21st Marine Battalion, at the very beginning of the Mandalorian Wars. During the first stage of the battle, the Aurek fighters of the 5th were responsible for destroying a Mandalorian Jehavey'ir-class attack ship.