At the creation of the New Republic, the former Alliance Fleet consisted primarily of donated starships converted to military duty, volunteer resistance force fleets and a small number of vessels purchased with limited Rebel Alliance funds, headed by Admiral Ackbar, who also held a seat on the New Republic Provisional Council. During this period, Ackbar coordinated the Fleet towards the Council's primary goal: the capture of Coruscant. Along the way, the Fleet engaged a number of Imperial warlords and relied heavily upon its officers' ingenuity to defeat the warlords' superior warships.
After the liberation of Coruscant, the New Republic reorganized under the Common Charter, which also organized the military might of the New Republic into a single, unified command structure, the Combined Defense Forces of the New Republic. Starships, starfighters and soldiers all served under the Supreme Commander, an office built from the remains of the Minister of Defense, Minister of the Army, Minister of the Navy and the Minister of the Starfighter Corps. While the Defense Force was organized into Fleet Command, Intelligence, Technology and Quartermaster sections, the Defense Fleet served as its primary action body, and was led directly by the Supreme Commander, Ackbar.
Ostensibly it was during this period that the Navy began to organize into fleets. These groups patrolled segments of the New Republic on a rotating basis, with at least one always assigned to defending Coruscant and another assigned to patrolling "Thunder Alley". Prior to 16 ABY, four fleets were created to fulfill this function.
In the nine years following the reorganization of the fleet, the variety of vessels that comprised the Defense Fleet grew; starships from hundreds of shipyards across New Republic space made up the frontline, support and civilian vessels of the Fleet. The resulting inefficiencies of this diversity prompted a program to streamline the Fleet's ships and increase maintenance efficiency. This program, named New Class, offered the Fleet a new level of standardization, power and flexibility previously enjoyed by the Imperial Starfleet. By 16 ABY, a new fleet, the New Republic Fifth Battle Group constructed wholly of New Class starships completed its proving missions and demonstrated the success of the program in the Black Fleet Crisis.
Ignoring Imperial design philosophy and opting for a larger number of smaller ship-designs, the New Republic built fleet carriers, Republic-class Star Destroyers and smaller battle cruisers, shying away from Super Star Destroyer-sized warships. However, the Navy's fleets were designed as response forces and, despite the concerns of some politicians during the launch of the Fifth Fleet, not a tool of conquest. The lessons learned from the Black Fleet Crisis eventually took form as the Star Defender program, which had its own set of detractors and moved ahead slowly.
Thus, the Navy was not able to easily launch counter-offensives against the Yuuzhan Vong in the late stages of the Yuuzhan Vong War, and once again had to rely on its talented commanders to achieve victories. During that conflict, Mediator-class battle cruisers, Bothan Assault Cruisers and Viscount-class Star Defenders comprised the fleet's "signature ships". With the collapse of the New Republic and the formation of the Galactic Alliance, the New Republic Defense Fleet formally ceased to exist, and was replaced by the Galactic Alliance Defense Fleet.
The Defense Fleet, and the Defense Forces as a whole, were headed by the Supreme Commander, who took orders from the Chief of State, the civilian leader of the New Republic. In the first few years after Endor, the Defense Forces were organized under the Ministry of Defense, which had been reorganized from the Rebel Alliance's Ministry of War, with separate a ministry below it for the Fleet. In practise this proved overly-bureaucratic and cumbersome, and following the Liberation of Coruscant in 6 ABY, the whole command structure was reorganized again, with the position of Minister of Defense being abolished the Supreme Commander becoming a Ruling Council position.
New Republic High Command was the senior professional military body in control of the Defense Forces, which in turn controlled Fleet Command. The New Republic Fleet Office was another controlling element of the Defense Fleet, which had authority over the Fleet, New Republic Fleet Intelligence, and the New Republic Marines.
The New Republic Marines, bridgehead commandos responsible for leading planetary assaults, were a component of the Defense Fleet. New Republic Fleet Intelligence was another component of the Defense Fleet responsible for military intelligence, which included Asset Tracking, a department responsible for tracking Imperial military equipment lost after Endor.
The Defense Fleet was built around four main fleets and area commands, derived from the four original fleets that had conducted the advance on Coruscant from 4 to 6 ABY. Early organization emphasized flexibility, with pre-existing squadrons and flotillas from the old Alliance Fleet remaining intact and local loyalties being taken into account. Battle groups were designed so they could be shifted within the four main fleets as required or if necessary deployed independently, such as the Solo Fleet deployed against Warlord Zsinj.
As the New Republic grew, Admiral Ackbar was faced with the challenge of creating a unified navy out of the disparate units that had comprised the Rebel Alliance's Sector Forces, which had contrasting regulations, tactics and traditions. To achieve this, the squadrons that had not originally been part of the central Alliance Fleet Command were largely broken up and their ships and crews sent to different units. This provoked a degree of resistance, and the Bothan Council and the Corellian Resistance responded by withdrawing most of their units from the navy, but on the whole Defense Fleet integration proceeded quickly. By 8 ABY, the New Republic First Fleet guarded Coruscant as the Home Fleet, while the Second defended Elom, the Third, Kashyyyk and the Fourth, Bothan Space. This arrangement fought in the Thrawn campaign, the Imperial advance out of the Deep Core, and Operation Shadow Hand.
By 12 ABY the battle group and squadron forces met standards for strength, unity and discipline, allowing a more sweeping military reform. All federal military forces were placed under the four fleet commands as part of a integrated Defense Force. Naval battle groups became subcommands with defined sectors of operations, with large forces blockading the main Imperial holdouts and smaller squadrons assigned to peacekeeping patrols inside New Republic territory. One battle group in each fleet served as a mobile reserve, but temporary attachments of multi-role task forces could turn each battle group into a powerful fighting fleet. These task forces were standardized squadrons built around a mix of vessels with complementary capabilities, designed to perform equally well at different mission profiles. The standard deployment was three Star Destroyers or heavy cruisers, with two light carriers, four escorts, and five attack ships. Also attached were a line of scouts and support vessels. Standing orders mandated that the balance of ships in each task force should be roughly equal rather than allowing battleships or pickets to become overrepresented, so that the number of task forces in a battle group defined its role rather than the internal balance of ships.
After the reorganization led to the four fleets becoming increasingly tied-down as territorial deployments, a new rapid-reaction command was activated in 16 ABY. The Fifth Roving Battle Group contained five task forces, and fought with distinction in the Black Fleet Crisis. The Fifth Battle Group was soon assigned full fleet status, and by 19 ABY the New Republic Fifth Fleet was enlarged to a full strength of five hundred capital ships in five battle groups.
- "Black Curs Blues"—Star Wars Adventure Journal 8 (Mentioned only)
- Star Wars: X-Wing Rogue Squadron: Battleground: Tatooine
- Star Wars: X-Wing Rogue Squadron: The Warrior Princess
- Star Wars: X-Wing Rogue Squadron: Requiem for a Rogue
- Star Wars: X-Wing Rogue Squadron: In the Empire's Service
- X-Wing Rogue Squadron 25: The Making of Baron Fel
- Star Wars: X-Wing Rogue Squadron: Family Ties
- Star Wars: X-Wing Rogue Squadron: Masquerade
- Star Wars: X-Wing Rogue Squadron: Mandatory Retirement
- (As "New Republic Navy")
- Luke Skywalker and the Shadows of Mindor
- X-Wing: Rogue Squadron
- X-Wing: Wedge's Gamble
- X-Wing: The Krytos Trap
- X-Wing: The Bacta War
- X-Wing: Wraith Squadron
- X-Wing: Iron Fist
- X-Wing: Solo Command
- "Crisis"—The DarkStryder Campaign (Mentioned only)
- Heir to the Empire (First appearance)
- Dark Force Rising
- The Last Command
- X-Wing: Isard's Revenge
- Dark Empire
- Dark Empire II
- Empire's End
- Crimson Empire
- I, Jedi
- Children of the Jedi (Mentioned only)
- X-Wing: Starfighters of Adumar
- Star Wars: Jedi Knight II: Jedi Outcast
- Star Wars: Jedi Knight: Jedi Academy
- Before the Storm
- Shield of Lies
- Tyrant's Test
- Ambush at Corellia (Mentioned only)
- Assault at Selonia
- Specter of the Past
- Vision of the Future
- Star Wars: Union
- Vector Prime
- The New Jedi Order: Dark Tide I: Onslaught
- The New Jedi Order: Dark Tide II: Ruin
- The New Jedi Order: Agents of Chaos I: Hero's Trial
- The New Jedi Order: Balance Point
- X-Wing: Mercy Kill (Mentioned only)
- Heir to the Empire Sourcebook
- Dark Empire Sourcebook (As "New Republic fleet")
- "Recon & Report: The Journey to Coruscant"—Star Wars Adventure Journal 2
- The DarkStryder Campaign
- The Essential Chronology
- The New Essential Chronology
- Starships of the Galaxy, Saga Edition
- The Complete Star Wars Encyclopedia
- The Essential Atlas
- The Essential Guide to Warfare