The Federal Erusean Navy boasted that its "invincible" Aegir Fleet was untouchable and unsinkable by any form of enemy attack. It was one of the most highly skilled, highly equipped, and highly trained in the region, and for most of the Continental War, the Erusean Navy dominated the waters surrounding the Usean continent.
After the Continental War, the Erusean Navy reduced in size, but rebuilt slowly, with both its reserve Rán Fleet and the powerful Njord Fleet. Erusea later purchased the advanced submersible aviation cruiser Alicorn from Yuktobania in 2012, bolstering the now Erusean Royal Navy even further. Despite its strength, the Erusean Navy was decimated during the Lighthouse War.
It is unknown to what extent the Federal Erusean Navy was active during the early stages of the war between Erusea and the Independent State Allied Forces. Regardless, the Aegir Fleet's reputation appeared to dissuade the ISAF from confronting the fleet head-on with its own naval forces. However, after attempts to bomb ISAF's GHQ failed, the Aegir Fleet was deployed to spearhead the invasion of North Point and bring about Erusea's total victory. The Aegir Fleet left the Erusean capital, Farbanti, on the west coast and made port at Comberth Harbor sometime before November 7, 2004. Erusean naval command scheduled the fleet to quickly refuel and resupply before making its way up the east coast to North Point.
However, ISAF squadrons interdicted the fleet's resupply convoys and destroyed a petrochemical complex that was the fleet's only fuel source. The Erusean military lost a stockpile of five million barrels of crude oil, and the Aegir vessels were effectively immobilized within Comberth Harbor. Erusea's plans to invade North Point were indefinitely stalled, and the fleet was ordered to await further attempts to rearm and launch.
On November 23, ISAF launched a surprise air raid on Comberth with the goal of sinking the Aegir Fleet while it lay at anchor. The damage and casualties were immense: all of the fleet's major vessels were either irreparably damaged or completely sunk, and the loss of manpower and reserve supplies was an equally costly blow. After the loss of its "invincible" fleet, the FEN lost its grip on the waters around Usea, and the ISAF Navy would begin to take a more active role in future ISAF operations.
When the ISAF attempted to retake Istas Fortress in southern Usea, FEN gunboats patrolled the deep inland waterways around the fortress and defended the facility. Once again, ISAF squadrons inflicted heavy damage of the Erusean forces, and the FEN lost several submarines stationed at the fortress's underground submarine docks.
By September 2005, the ISAF had pushed the Erusean back to their capital, Farbanti , and laid siege to the city. A FEN battleship crew, in an act of desperation, ran the ship aground near Silver Bridge and opened fire on the ISAF tanks that attempted to cross it. To the north, an Erusean destroyer positioned itself near Johnson Memorial Bridge in order to secure the airspace around the Erusean reinforcements' route. One of the remaining Erusean submarines positioned itself between the submerged buildings in Farbanti's flooded municipal district. The Erusean warships attempted to bombard the advancing allied ground units but were ultimately sunk by ISAF fighters during the siege. ISAF would accept Erusea's unconditional surrender later that day.
In 2006, following Erusea's reestablishment of its government, a number of the Federal Erusean Navy's surviving assets, including an aircraft carrier, joined the militant group known as "Free Erusea" and staged an uprising against the ISAF. Ace pilot Mobius 1 sunk the Free Erusea naval vessels, and the insurrectionists were forced to surrender once their base of operations was destroyed.
In December 2012, the Erusean Navy acquired the submersible aviation cruiser Alicorn from GR Marine and Ships, who had refurbished and upgraded the ship after purchasing it in turn from Yuktobania. The submarine was launched on New Years Day in 2015, but went missing on its sea trials in the Spring Sea during November 2016. The ERN was forced to admit the sub was missing, but assured the public that no radioactive materials were released into the ocean and that maritime safety was not compromised. The missing Alicorn was discovered two years later in October 2018 at the bottom of the sea, and the majority of the crew was safely rescued. It was sent to the reserve fleet and was investigated to find the original cause of the accident. The submarine never entered service.
During the 2019 Lighthouse War, the Erusean Navy was involved in hostilities against the Osean Federation. The opening Erusean surprise attacks at the opening of the War left Osean naval power limited, as Osea's vaunted carrier groups were either damaged in port, sunk around the International Space Elevator or at sea. Erusea's Njord Fleet would press this advantage by establishing a supply base at Snider's Top, threatening any Osean counterattack through northern Usea. However, the Njord Fleet was decimated in an Osean surprise strike.
In response, the Erusean Navy sought to commission the Alicorn, which had been held in the reserve fleet. However, the submarine unexpectedly went rogue when its commander, Matias Torres, declared it separate of the Erusean Navy. As a further measure, the Erusean Navy mobilized its reserve fleet, made of mothball ships, to oppose Osea's expected attacks on the west coast. Osea caught wind of these efforts and the fleet and mothballed ships were sunk during an raid on Anchorhead that also killed multiple high ranking Erusean naval officers, leaving only token and leaderless naval forces to defend Farbanti. The rogue Alicorn, meanwhile, was sunk with all hands during an Osean operation to prevent a nuclear strike on the Osean capital, Oured. The remaining naval forces faced an Osean surface group during the Battle of Farbanti, but were sunk during the battle.
The actions of the Erusean Navy after the Kingdom's collapse were limited. Gunboats from the Radical faction were seen during a three-way battle at Anchorhead. Frigates under the Conservative faction were deployed against Radicals and Osean forces at Tyler Island but were sunk from air attacks by the Long Range Strategic Strike Group.
- F-4E Phantom II
- F-14A Tomcat
- F-14D Super Tomcat
- F/A-18C Hornet
- F/A-18F Super Hornet
- Rafale M
- Su-33 Flanker-D
- Ticonderoga-class guided-missile cruiser (CG)—designated "aegis"
- Iowa-class battleship (BB)
- Kitty Hawk-class aircraft carrier (CV)
- Hatakaze-class guided-missile destroyer (DDG)—designated "cruiser"
- Cassard-class frigate (FF)—designated "destroyer"
- Los Angeles-class nuclear-powered submarine (SSN)
- Beowolf π
- Beowolf ν
- La Fayette-class frigate (FLF)
- Pegasus-class hydrofoil (PHM)
- Murakumo-class patrol craft (PC)
- San Giorgio-class amphibious transport dock (LPD)
- Towada-class replenishment ship (AOE)
- Landing Craft Air Cushion (LCAC)
- Kirov-class battlecruiser
- Slava-class cruiser
- Admiral Gorshkov-class frigate (fictional Aegis configuration)
- Udaloy-class destroyer
- Alicorn-class submersible aviation cruiser
- Cutscene before Unexpected Visitor, Ace Combat 7: Skies Unknown.
- SP Mission 02: "Anchorhead Raid", Ace Combat 7: Skies Unknown.
- Blockade, Ace Combat 04: Shattered Skies.
- Lifeline, Ace Combat 04: Shattered Skies.
- Invincible Fleet, Ace Combat 04: Shattered Skies.
- Tango Line, Ace Combat 04: Shattered Skies.
- Siege of Farbanti, Ace Combat 04: Shattered Skies.
- Arcade Mode, Ace Combat 5: The Unsung War.
- Mission 11: "Fleet Destruction", Ace Combat 7: Skies Unknown.
- Mission 15: "Battle for Farbanti", Ace Combat 7: Skies Unknown.
- Mission 16: "Last Hope", Ace Combat 7: Skies Unknown.
- Mission 17: "Homeward", Ace Combat 7: Skies Unknown.
- File:Alicorn Runway Specs.png.