Osborne, who had secretly survived Crow's assassination attempt, planted his top Ironblood into the Noble Alliance as its Chief of Staff, granting him a favorable vantage point in the war and allowing the Imperial Resistance to gain victory. The aftermath of the war resulted in the weakening of Erebonian nobility, strengthening Osborne's foothold in the country, and led to the Imperial occupation of Crossbell as well as Osborne stealing the Phantasmal Blaze Plan from Ouroboros (who assisted the Noble Alliance in pursuit of that plan).
There were two factions vying for power in Erebonia. The first, the Noble Alliance, was led by Duke Cayenne, and sought to maintain the current status quo. The second, the Reformist Faction, was led by Chancellor Giliath Osborne, and sought to remove the social and political influence of the nobility. To combat the Reformists, Duke Cayenne funded the Imperial Liberation Front (ILF), a terrorist group which opposed Osborne's policies and ideals.
The first action of the ILF was on 28 June S.1204 and was to attack the Imperial Watchtower located in the Nord Highlands in an attempt to trick the Imperial Army into viewing the attack as originating from a nearby Calvard Republic airbase, thus igniting a war between the two nations. This plot was foiled by Class VII finding and defeating the mastermind of the operation, Michael Gideon.
Almost one month later, on 26 July S.1204, the ILF kidnapped Elise Schwarzer and Princess Alfin Reise Arnor during the Summer Festival in Heimdallr. They escaped into the catacombs below the city, until they were once again cornered by Class VII, and released their hostages shortly after.
On 31 August S.1204, the ILF attacked Garrelia Fortress during the West Zemuria Trade Conference in an attempt to launch the railway guns stationed there and attack Crossbell City. Once again their plans were stopped by Class VII, who happened to be there at the time.
Course of the War
Occupation of Heimdallr
During the morning of 30 October 1204, Chancellor Giliath Osborne is assassinated by ILF ringleader Crow Armbrust, immediately following which the Noble Alliance deploys their newly developed Panzer Soldat units, which are easily able to overwhelm the imperial forces due to their high manoeuvrability. The imperial family as well as Governor Carl Regnitz are taken into custody and held within Karel Imperial Villa. Over the next month most of Erebonia is taken over by the Noble Alliance, and Crow Armbrust is given the title "Azure Chevalier", derived from the colour of his Divine Knight, Ordine.
On 10 December S.1204, Class VII is entrusted with the Courageous by Prince Olivert Reise Arnor, and declares themselves a third faction in the war, independent from both the noble and imperial sides. One week later, they assist the 4th Armored Division in retaking the Twin Dragons Bridge from noble control, marking the turning point in the war.
Following this, in an attempt to demonstrate his power to the people of Erebonia, Duke Albarea has his provincial army burn down the town of Celdic on 23 December S.1204. In retaliation for this, two days later, the 4th Armored Division and the Railway Military Police (RMP) launch a joint invasion of the Kreuzen Province with the assistance of Class VII. The invasion succeeds, Duke Albarea is arrested and the provincial capital Bareahard is placed under Imperial control.
On 30 December S.1204, the soldiers defending Trista, located on the outskirts of Heimdallr, are recalled to help protect the capital. This allows Class VII to easily take the town back, which provides the RMP a nearby base for the retaking of Heimdallr.
Liberation of Karel Imperial Villa
The next day, the RMP and the Imperial Army begin their invasion of Heimdallr, while Class VII is asked to liberate Karel Imperial Villa, where the imperial family is being held. Immediately following the liberation, Vita Clotilde summons the Infernal Castle and Duke Cayenne holds Crown Prince Cedric Reise Arnor captive at the top. After Class VII confronts and defeats Crow and the Vermillion Apocalypse, Giliath Osborne reveals he is still alive, and Duke Cayenne, the leader of the Noble Alliance, is arrested.
Shortly after, during the month of January S.1205, the Noble Alliance declares full collaboration with Chancellor Osborne, ending the Erebonian Civil War.
Occupation of Crossbell
With the bolstered military forces of Erebonia resulting from the civil war, the Imperial Army invades Crossbell State, and captures Crossbell City in a single day. On 14 January S.1205, Crossbell signs a treaty with Erebonia, losing its autonomy and becoming a province of Erebonia. Two months later, in March S.1205, Rufus Albarea is appointed Governor of Crossbell, and it is announced that Crossbell will formally merge with Erebonia.