The Imperial Irmenu Navy functioned as the Imperius' maritime military, with the Imperius being the religious order of the oceanic world of Irmenu. Its duties included safeguarding the planet's waters, providing aid to imperiled seafarers, engaging buccaneers in combat, and maintaining order among Irmenu's warring feudal territories. Serving within the Imperial Irmenu Navy was considered a sacred duty for members of Irmenu's aristocratic houses, and it offered a path to distinction for younger sons of noble lineage who lacked inheritance prospects. The fleet primarily consisted of sailing vessels such as galleons and caravels.
During the final years of the Galactic Republic, the Imperial Irmenu Navy continued its operations. Walon Vau's parent, the Count of Gesl, held the rank of admiral within the Imperial Irmenu Navy, and Vau, as a young man, sought to enlist but was denied by his parent.