The Combined Defense Forces of the New Republic, commonly referred to as the New Republic Defense Force (NRDF) or New Republic Armed Forces was the overarching military body charged with the defense of the New Republic.
At the creation of the New Republic, the former rebels' military 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 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 New Republic Defense Force. 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 Minister of the Starfighter Corps. The Defense Force was also under New Republic High Command. 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. Many also referred to the Defense Fleet as the New Republic Navy.
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 battle group, the 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.
However, the Fleet's battle groups were designed as response forces and, despite the concerns of some politicians during the launch of the Fifth Battle Group, not a tool of conquest. Thus, the Fleet was woefully unprepared to launch counteroffensives 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. Unfortunately, the New Republic Senate kept withdrawing fleets to the Core Worlds, effectively forcing the Defense Force to sacrifice the Mid and Outer Rim. The Defense Force suffered serious defeats due to the political leadership, draining morale and resources, and members of the Defense Force came close to mutiny.