Alliance Navy: Humanity's Fleet

The Alliance Navy was the space combat branch of the Systems Alliance military, responsible for protecting human colonies, space stations, and the mass relays. One of the greater naval forces in Citadel space, it was known to number at least several thousand ships, and its military prowess drew the attention of the Citadel Council. The Alliance Marines, the ground operations branch of the human military, were a specialized arm of the Navy.

Doctrine and composition#

The Navy was a space combat force charged above all with protecting human colonies, space stations, and the mass relays. Rather than spreading its strength thin, it stationed only token garrisons to guard Alliance colonies and concentrated its power in fleets posted at mass relay nexuses, where they could respond with overwhelming force to any colony under attack. The Council, while wary of the possible outcome of another war between humans and turians, was also keen to harness the Navy's peacekeeping potential in unstable regions like the Skyllian Verge and the Attican Traverse, and its strength helped make humanity an attractive prospect as the newest Council species.

At the time of the First Contact War in 2157 the Navy possessed over 200 vessels, including several dreadnoughts, divided into at least two fleets. By 2186 and the onset of the Reaper War it had grown to nine dreadnoughts spread across at least eight fleets. Each fleet was subdivided into flotillas built around a cruiser and four to six frigates, and fleet units were supported by fighters and dedicated interceptors deployed from cruisers, dreadnoughts, and carriers. During the First Contact War the Navy still operated smaller destroyer-class vessels with crews as small as twenty, but these later evolved into frigates.

Vessels and naming conventions#

The Navy's ships followed strict naming conventions: dreadnoughts were named for mountains on Earth, cruisers for cities, frigates for great battles in human history, and carriers for great leaders, artists, and intellectuals. The "SSV" prefix borne by Alliance warships stood for "Systems Alliance Space Vehicle."

Dreadnoughts formed the heaviest line of the fleet, with two classes in service: the older 888-meter Everest class, whose main gun could accelerate a twenty-kilogram slug to over one percent of the speed of light for a yield equivalent to tens of kilotons of TNT, and the newer Kilimanjaro class, armed with scores of broadside mass accelerator cannons. Cruisers carried more firepower and protection than frigates while remaining more maneuverable than dreadnoughts, forming the backbone of the fleet and leading frigate flotillas in small engagements. Frigates served as light escort and scouting vessels, fitted with GARDIAN defense turrets and torpedoes and organized into "wolf pack" flotillas that used their speed to strike ships whose kinetic barriers had failed. The fighter carrier was a uniquely human design, a dreadnought-sized ship that traded heavy guns for extensive hangars and relied on fighters and interceptors as its primary armament.

Fleets#

The Navy was divided into numbered fleets, most of which were mobilized to defend the galaxy at the onset of the Reaper invasion. The First Fleet, the largest, was based at Arcturus Station and guarded the relay connecting to the Sol system, serving as a reactionary force able to answer attacks across several clusters. The Second Fleet, commanded by Admiral Kastanie Drescher during the First Contact War, had liberated Shanxi from turian occupation. The Fifth Fleet, also known as the Arcturus Fleet, was Admiral Hackett's command and frequently supplied Commander Shepard with Alliance assignments; it was awarded the Palladium Star for its part in the Battle of the Citadel.

The 63rd Scout Flotilla formed part of the Fifth Fleet under Rear Admiral Mikhailovich, and the Normandy was originally slated for assignment to it before being given over to Shepard to hunt Saren Arterius. The Navy also fielded marine detachments such as the 2nd Frontier Division, a garrison based on Eden Prime that was all but wiped out when Saren and his geth army attacked the colony.

The Battle of the Citadel#

The Alliance Navy was instrumental in saving the Citadel when the station came under attack by the Reaper Sovereign and Saren's geth in 2183. With the Citadel Fleet cut off by the locked-down mass relays and under heavy fire, the Alliance Navy was the only force large enough to provide reinforcements. Depending on the orders given during the crisis, the Fleet either sustained heavy losses saving the asari dreadnought Destiny Ascension, or abandoned the flagship in order to concentrate all its firepower on Sovereign. Following the battle, Admiral Steven Hackett was appointed head of the Alliance Navy.

The Fall of Earth#

The Navy suffered the most devastating defeat in its history when the Reapers invaded in 2186 and drove toward Earth. The Sixth and Seventh Fleets, posted near Terra Nova and Eden Prime, were bypassed entirely as the Reapers committed to a headlong rush at humanity's homeworld. Knowing something was coming, Admiral Hackett moved the Second, Third, and Fifth Fleets to guard Arcturus Station, but when the Reapers arrived they sent a screen of capital ships to distract the defenders while the bulk of their force used the Arcturus relay to reach Sol. Hackett was ultimately forced to sacrifice the entire Second Fleet to let the Third and Fifth Fleets escape, leaving Arcturus Station, the Alliance capital and home to forty-five thousand people, to be destroyed.

At Sol, the Reapers immediately engaged the First Fleet at the Charon Relay, buying the Fourth Fleet in orbit around Earth a few minutes of warning. That final defense was quickly overwhelmed: the First Fleet was cut in half and sacrificed a tenth of its ships so the rest could escape and rejoin Hackett, while the Fourth Fleet was wiped out entirely as the Reapers began to land. The surviving fleets withdrew and regrouped under Hackett during the Reaper War, eventually returning for the climactic battle for Earth.