Thunder Alley was a region of space along the borders of the New Galactic Republic, and several fleets rotated to patrol. The Second Fleet had been patrolling Thunder Alley the longest of the fleets without home service and shipyard services. In 16 ABY, Gial Ackbar convinced Leia Organa Solo to pull the Second Fleet out and replace it with the First Fleet which had been Coruscant's defense force during the same time.