(Imperial Era) Aquarian Imperial Navy
During the Unification Protocol Act of 4402, and the subsequent transition of the Federal States into an Imperial Republic lead by the ATIS council, the UAS Federal Navy, also known as the Aquarian Federal Navy was disbanded and its command structure re-ordered into the new Aquarian Imperial Navy. AIN operates on largely the same principles as the AFN, but the Board of Admiralty now directly reports to the ATIS Council and the Chairman of the Imperial States, with no devolved command structure between the civilian government and military leadership.
The Aquarian Military underwent extensive re-structuring with the dawn of the Imperial Era, with the Navy, Planetary Forces and Marine Corps reporting directly to the government; the ATIS Council. Such restructuring was deemed necessary to ensure the Navy was able to respond to developing threats with greater efficiency. The Aquarian Imperial Navy remains the backbone of the Terran military in the Aquarius cluster, a mantle it carries forward from the UAS Federal Navy and the esteemed Old Federal Navy before it. Despite such a prestigious position, there are many within Aquarius that see the Imperial Navy not has a force to protect the Terran way of life, but as the first sword of oppression, wielded by an authoritarian regime. Regardless of politics, the Aquarian Imperial Navy is the largest and most powerful single military organisation in known human history; operating a vast fleet of technologically advanced and highly automated warships at the forefront of humanity's expansion into the stars - both the first, and last, line of defence against an uncertain future.
The Aquarian Imperial Naval command structure largely reflects the previous incarnations, the UAS and Old Federal Navies; each sector is allotted an independent Branch of the Navy, with its own command structure and fully independent sortie capability. There are five branches; Home Sector, Tempest, Angel, Phoenix and Outer Sector. Each branch is overseen by its Supreme Sector Admiral of the Fleet (Sector Admiral) who occupies a position on the Board of Admiralty; which reports directly to the Chairman or Chairwoman of the ATIS Council. It is within this board that co-operation between Sector Fleets is organised, as each branch technically operates as a fully independent fighting force.
Within each Branch, there are multiple sub-fleets, each consisting of multiple Task Groups and Task Forces. Each of the granular organisations operating its own command structure reporting to an executive officer; Fleet Admiral for a Sub-Fleet, and Rear Admiral for a Task Group or Force. The structure of the Imperial Navy is established to allow rapid response and highly efficient co-ordination to developing threats, which, by the 5th millennium - could have grave consequences for humanity's ultimate survival.