The One Week War

The One Week War「一週間戦争」or The Three Front War「三正面戦争」(in the Web Novel its referred as The Five Day War), was the conflict between the Elfrieden Kingdom, the Principality of Amidonia and the Three Dukes. This would be the first military action performed by the newly-instated ruler of Elfrieden, Kazuya Souma. The outcome of this conflict was the disbandment of the Army, Air Force and Navy of the Three Dukes, the formation of a combined Armed Forces Military, the annexation of Amidonia, and the formation of the Kingdom of Friedonia. The war officially begin from "32nd Day, 9th Month, 1546 Year of Continental Calendar" and ends on the 37th day.

Prelude

 * Principality of Amidonia offers assistance to both Elfrieden and the Three Dukes, with the hidden agenda of regaining territory lost in the war with Elfrieden 50 years ago.
 * Kazuya Souma dismisses the services of the Mercenary State of Zem and holds a Final Counsel with the Three Dukes to determine their allegiance and discuss his plan to create a combined Armed Forces Military.
 * Excel Walter, leader of the Navy, pledges her loyalty to Elfrieden. Castor Vargas, leader of the Air Force, and Georg Carmine, leader of the Army, openly rebel.
 * Upon hearing of the rebellion, Gaius Amidonia and Julius Amidonia lead their army of 30,000 over the Ursula Mountains and into Elfrieden territory towards the fortress of Altomura. Unknown to them, Excel was already stationed at the fortress during the time of the Final Counsel and had sworn her allegiance to Kazuya days ago.
 * Before the Amidonian Army reaches Altomura, Kazyua sends out a request for all adventurers to evacuate the nearby villages in the army's path. It is under the pretense of protecting the villagers from the Flame Pierrots. Unknown to all, they are merely dolls being controlled by Kazuya. The dolls also delay the Amidonian army in its march.

Day 1

 * The Amidonia Army lays siege to the Fortress of Altomura, but are unable to attack due to the stalling tactics employed by the defenders. As a result, the invaders are held back until Day 2.
 * Elfriden Forces are sent to Georg Carmine's Duchy to put down his rebellion and the corrupt nobles he is sheltering. They erect a temporary fortress to lay siege. The day is a sequence of small skirmishes and confrontations. Neither side gains an advantage, though Carmine's side loses 3 large cannons due to the impatience and ineptitude of the corrupt nobles. Mercenary soldiers prove to be unreliable. Unknown to the corrupt nobles, it is Georg Carmine's plan to intentionally lose the battle.
 * Red Dragon Castle is attacked by the Battleship Albert, using it like a mobile artillery.
 * Carla Vargas leads the Air Force wyverns to assault the Albert and capture Kazuya Souma. However, this is revealed to be a diversion to lead her away from Red Dragon Castle and leave Castor vulnerable.
 * Castor is captured by a strike force led by Souma. Carla is also taken prisoner and the Air Force is now under Souma's command.

Day 2

 * Using the Air Force now under Souma's command, Elfrieden takes Randell Castle and defeats Georg Carmine's forces. All corrupt nobles are taken prisoner and later executed.
 * With the two rebelling Dukes now defeated, Kazuya announces his intent to invade Amidonia and capture the city of Van.
 * Upon hearing of the imminent invasion of their home country, the Amidonia Army abandons its siege of Altomura and begins a withdrawal.
 * Due to the muddy terrain on the return trek, (left as a booby trap by Elfrieden), Gaius and Julius lose a staggering amount of men and supplies from exhaustion, death and desertion. They also suffer an ambush by a commando group led by Juna Doma. Their number is cut down to 15,000.

Days 3 and 4

 * The Amidonia Army is delayed further on their march to Van, as they encounter disease, food and water shortages and desertion. They resort to conscripting peasants to rebuild their ranks back up to 25,000.

Day 5

 * The Amidonia Army finally reaches the outskirts of Van, only to find that the Elfrieden forces are already there. The enemy is well-rested and ready, while the Amidonians are tired, hungry and desperate.
 * The Elfriedens number 50,000 while the Amidorians number 25,000.
 * Though the Amidonia Army puts up a fight, defeat eventually becomes inevitable. Gaius is killed during a suicidal charge in an attempt to kill Souma. Julius manages to escape, but cannot muster enough forces to re-take Van.

Aftermath

 * While only losing the capital city of Van, Amidonia had failed in its attempt to re-take its lost territories. As a result, the borders between Amidonia and Elfrieden had changed, thereby forcing the Gran Chaos Empire to intervene and invoke the First Clause of the Mankind Declaration Treaty.
 * Van is occupied for over a month, and its citizens enjoy the food aid, entertainment and freedoms granted by the occupiers.
 * After lengthy negotiations, Van is returned to Amidonia, though the country is now forced to paying reparations due to invading Elfrieden in the first place.
 * Georg Carmine commits suicide, after revealing it was his intention of gathering all the corrupt nobles in one place so they could be captured and purposely losing to Elfrieden.
 * Castor Vargas is spared the death penalty for rebellion and is placed under the command of his Mother-In-Law, Excel. Carla Vargas is also spared and is made a slave under Kazuya Souma.
 * One month after the return of Van, revolts and rebellions occur all over the country, due to Julius' attempts to erase all Elfrieden influences, and restricting the newly-found freedoms of his people.
 * During Julius' attempt to put down a major rebellion in the northwest, the city of Van revolts and pledges allegiance to Elfrieden. This results in Elfrieden occupying the city again.
 * The Amidonian Army cannot handle the numerous rebellions and is weakened even further due to the high rate of desertions.
 * Julius is forced into exile and flees to the Union of Eastern Nations as a refugee
 * During this period of turmoil, both the Republic of Turgis and the Lunaria Orthodox Empire direct their forces toward Amidonia. For the former, it was to gain warmer and more farming areas. For the latter, it was under the pretense of protecting followers of their faith. The Republic actually invades Amidonia and attacks Nelva, while the Papal State begins to buildup its forces at the northern border.
 * The forces of Turgis were stalled by General Herman Neumann and former Finance Minister Gatsby Colbert. The Lunarian Army ceases its buildup and decides not to confront the Elfrieden forces at Van,
 * The Army of the Republic of Turgis withdraws due to the threat of invasion by the naval forces led by Excel Walter
 * Amidonia ceases to be an independent nation as it is annexed by Elfrieden and becomes part of the Kingdom of Friedonia.

Changes from WN to LN
Some scenes were removed/changed during the novelization of WN.
 * During prelude, unknown to Castor, the entire Final Counsel was publicly broadcast to the people of the Vargas Duchy.
 * During Day 1, Castor is besieged by the angry citizens of the Vargas Duchy, who resent him for rebelling and denying them the food and economic aid offered by Souma.