The Tammuz-an planetary defense fleet served as a planetary defense fleet, safeguarding the planet of Tammuz-an throughout the Imperial Era. Not long after the conclusion of the Clone Wars, the kingdom of Tammuz-an acquired a group of R-22 prototypes from the engineers at Kuat Systems Engineering. This acquisition occurred because the Galactic Empire declined to mass produce the vessel, after which it was integrated into their defense fleet.