It represented the first expansion of the Galactic Alliance naval structure beyond the five battlegroups which had comprised the main force of the Fleet under the former New Republic, and probably still in the early years of the new government.
Well before the end of 40 ABY, however, it had been joined by the Seventh, Eighth and Ninth Fleets.
By 40 ABY the Sixth fleet was under the direct command of Admiral Nek Bwua'tu along with the First Fleet as it took part in the weeks-long Battle of Kuat. In 44 ABY, it was in charge of guarding the space directly above Coruscant.
- The Essential Atlas