Fall of the Re-Estize Kingdom

Fall of the Re-Estize Kingdom was a war between the Re-Estize Kingdom and the Sorcerer Kingdom that resulted in the dissolution of the former country. The Argland Council State and Adventurer's Guild also joined the conflict on the side of the Kingdom while the Slane Theocracy and Eight Fingers offered humanitarian aid by evacuating civilians.

Background
The war itself was triggered by the badly thought out actions by a single foolish nobleman of the Re-Estize Kingdom's New Faction. This was an attempt to increase the grain prices that the Sorcerer Kingdom had deflated due to their mass-produced high-quality grain imported to the Re-Estize Kingdom in order to turn a profit for his domain. His plan was to rob the Sorcerer Kingdom's Grain Transports in order to acquire it for himself, and cause a shortage of the product. At the same time, deflate the grain prices to make a profit from his own inferior stock and make even more profit by selling the stolen grains as his own product.

In other words, this incredibly foolish plot was hatched by the Nobleman in question together with the assistance of two other Barons. They all did this believing that, even if a war of retribution should break out between their nation and the Sorcerer Kingdom, the enemy nation does not possess the necessary numbers to invade the Kingdom. Even if they did only the territories and domains in the Kingdom's borders would be taken, far away from their own territories. Thus, the two felt safe enough to help their "leader" in his scheme and provide additional back-up for his forces. In truth, they would simply stand back in the sidelines just "in case" Philip would call for their assistance. This is while they are hoping their supposed leader Philip carried out the actual deed in order to prevent themselves from being identified or connected to him should the plot backfire.

When the merchant Christopher Olson ordered the mercenaries to abandon their grain caravan and retreat, Philip considers it his victory and that his plan was successful. However, Christopher recognized who Philip was and decided that it is safer to leave the grain behind as killing this noble could anger his superior Hilma Cygnaeus. More-ever because of his lack of foresight or insight, the nobleman in question didn't even bother hiding his involvement to the incident. Even going so far as to arrogantly/foolishly flaunt the Sorcerer Kingdom's flag as a "War Prize" based on his successful "Battle of Conquest" against the Sorcerer Kingdom, believing that it would garner him support and praise back at the Royal Capital and not bother hiding his actions at all.

Caught completely off guard by this unexpected occurrence, the Sorcerer Kingdom had initially thought that this incident was the doing of another unknown third party who had manipulated or mind controlled the noble in question in order to initiate a complex plot. Hence, they immediately began preparing countermeasures to this "new enemy" before the Sorcerer King accurately figured out that it was in fact nothing more than the Nobleman in question's own stupidity and vanity getting the better of him. Due to their prior plans of conquering the kingdom anyway using more peaceful methods now being ruined because of that nobleman's actions, the Sorcerer Kingdom thus then decided to further expand their initial plans further and take full advantage of the situation in order to make an example of the Re-Estize Kingdom as well as conquer it. This was done so in order to send a message to all other nations not to antagonize them or underestimate the Sorcerer Kingdom as the Re-Estize Kingdom so foolishly had. Due to realizing the probable increase in foreign interaction or even covert operations against the Sorcerer Kingdom by other Nations.

Sorcerer Kingdom's Covert Invasion
While the Sorcerer Kingdom announced that their invasion would commence in a month, this was an elaborate ruse and they actually invaded immediately. Marching their armies over the border, they launched attacks on the Kingdom's western regions and massacred the inhabitants to prevent the Kingdom's government from learning of the invasion. Like this, they encircled the capital and cut the Kingdom off from its allies.

The only survivors of these attacks were domains that had been selectively coerced into switching sides.

Battle of E-Naeurl
While their invasion was an overwhelming success, the amount of violence used angered Nazarick's human symphathizers, who pleaded with Sorcerer King Ainz to halt the slaughter of innocent civilians. The monarch thus planned on losing a battle on purpose to appease them: the one for the port city of E-Naeurl. However, despite giving the city a fighting chance by only sending an army of low-ranking undead and giving them time to prepare by letting news of the invasion leak ahead of time, it initially looked like it would still end up being a massacre. Fortunately, just as all seemed lost, the city was saved by the arrival of the Adamantite-Ranked Azuth Aindra, who easily defeated the undead horde.

Despite the Sorcerer Kingdom's loss, the battle revealed the existence of a powerful new threat in the form of Azuth Aindra, and they subsequently began taking defensive measures. For the Kingdom; E-Naeurl became a humanitarian corridor through which civilians could flee the war to other countries, which the Sorcerer King hoped would keep his human sympathizers appeased.

Royal Coup
Following the Battle of E-Naeurl, the Kingdom's government finally became aware of the Sorcerer Kingdom's invasion. However, King Ramposa III insisted that there could still be a peaceful resolution to this conflict. Prince Zanac and his retainers, on the other hand, believed that the Sorcerer Kingdom had made their intent to destroy the Kingdom clear; thus, for the sake of the nation's survival, the Crown Prince overthrew his father in a quiet coup and subsequently began making wartime preparations.

Black Scripture's Covert Evacuation Plan
Following the Sorcerer Kingdom's declaration of war, the Slane Theocracy immediately saw that the Kingdom was finished. Still, the Theocracy had secretly invested a lot of resources in the development of the Kingdom; thus, in hopes of at least salvaging something from their initial project, they send the Black Scripture to the doomed country to recruit powerful adventurers in exchange for evacuating them to safety.

In the end, while failing to get some key individuals, many adventurers accepted the offer and migrated to the Theocracy.

Assassination of King Zanac
With news that the Sorcerer Kingdom's army was approaching the capital, King Regent Zanac drafted all able-bodied men in the city into the Royal Army and moved to intercept the enemy. However, upon witnessing the Sorcerer Kingdom's overwhelming forces and the final attempt at negotiations breaking down, several nobles, desperate to survive, ambushed and killed the King Regent.

Afterward, the treacherous nobles took the deceased Zanac's head and presented it to the Sorcerer King as a symbol of surrender, hoping to be spared in exchange. However, the monarch was instead outraged by the nobles' betrayal of their king and had them tortured to death.

Battle at the Re-Estize Plains
Disgusted by the nobles' betrayal and the assassination of Zanac, Ainz turned the conquest of the Kingdom into a large-scale massacre to completely wipe away the nation from the New World. The Royal Army are the first to feel his wrath and they are wiped out in an hour.

Eight Fingers' Evacuation Plan
Before the Sorcerer Kingdom's attack on the Royal Capital, Ainz had Shalltear Bloodfallen and Eight Fingers kidnap a large portion of the city's children and evacuate them from the warzone through teleportation magic in order to keep Nazarick's human symphathizers appeased. Eight Fingers themselves, and about a thousand people loyal to them, were also able to flee through this, effectively saving a decent amount of civilians.

Albedo vs Azuth Aindra
At the start of the invasion of Re-Estize, the armies of the Sorcerer Kingdom marched to destroy the city. They were briefly attacked by an interloper who was none other than Azuth Aindra. The adventurer goaded Albedo to pursue him, knowing full well that he had no chance of victory. The main purpose of his attack was to draw the Sorcerer King's protection so that his ally Tsaindorcus Vaision could assassinate the former.

Ainz Ooal Gown vs Riku Aganeia
Tsaindorcus confronted the Sorcerer King. Their battle was intense and deadly but it came to an end once reinforcements arrived to aid Ainz and Tsaindorcus fled before he was overwhelmed. Despite failing to kill Ainz, Tsaindorcus was confident that he can defeat Ainz the next time they met after learning his full capabilities. Unbeknownst to the Dragon Lord, however, the "Ainz Ooal Gown" he has faced was actually Pandora's Actor in disguise and the Sorcerer Kingdom had already deduced his true identity as the Platinum Dragon Lord.

Blue Roses Infighting
Despite the Kingdom being doomed, the leader of the Adamantite-Ranked Adventurer Group Blue Roses, noblewoman Lakyus Alvein Dale Aindra, intended to fight until the bitter end. However, the same could not be said for her comrades, who incapacitated and mind-controlled her to force her to flee with them.

Siege of the Royal Capital
With all hope for the Kingdom gone following Tsaindorcus' failure, the Sorcerer Kingdom attacks the Royal Capital. The Kingdom's last remaining soldiers would end up making their final stand during this battle. However, in the end, the capital fell with little resistance.

Raid on the Re-Estize Magician's Guild
While the battle in the capital waged on, one of the Sorcerer Kingdom's Sixth Floor Guardians, Aura Bella Fiora, used it as a cover to infiltrate the city and raid the Magician's Guild located there. While the famous swordmaster Vesture Kloff Di Laufen was guarding the guild, Aura easily killed him and completed her mission without any hassle.

Fall of Ro-Lente Castle
Third Princess Renner finally reveals her treason to the Kingdom by assassinating her own father, King Ramposa III. At the same time, the Sorcerer Kingdom besieges the Royal Palace and takes it in no time at all. Afterward, the former princess is welcomed to Nazarick as an honorary member.

Duel at Ro-Lente Castle
With no-one else left, Princess Renner's bodyguard, Climb, is forced to face off against Sorcerer King Ainz Ooal Gown by himself. Unbeknownst to him, though, his "heroic last stand" was merely a set-up designed to allow his mistress to maintain her good standing in front of him post-defection.

Massacre at Domain Montserrat
After taking the Royal Capital, the Sorcerer Kingdom's forces spread out to take the remainder of the country. Due to the Sorcerer King resolving to annihilate the Kingdom following the nobles' betrayal of Zanac, the result is a nationwide massacre as the Kingdom's remaining population is wiped out.

One particularly noteworthy massacre was the one at Domain Montserrat, the territory of Philip Dayton L'Eyre Montserrat, the very man whose actions directly led to the Sorcerer Kingdom's invasion. To avenge herself upon the man who ruined her initial plan, the Sorcerer Kingdom's prime minister, Albedo, personally led her nation's forces. She proceeded to kill all of the domain's inhabitants before torturing Philip to death, effectively erasing her previous involvement with the nobleman.

Aftermath
The Re-Estize Kingdom was left in ruins with only a small handful of survivors who managed to stay alive either by escaping before its downfall or submitting to the rule of the Sorcerer King. The only monument left of the Kingdom was Ro-Lente Castle which was left untouched whilst the entire royal capital was turned into a literal mountain of rubble and set ablaze by Guren to serve as a reminder to all of the consequences of going against the Sorcerer King and his kingdom.

The Fall of the Re-Estize Kingdom also caused the Sorcerer Kingdom's neighboring kingdoms to prepare themselves for what they believe to be an "inevitable" war with the Sorcerer Kingdom, as seen where Platinum Dragon Lord of the Argland Council State had attempted to assassinate the Sorcerer King and the Slane Theocracy had acquired additional manpower by assimilating some of the strongest and most talented Adventurers from the doomed Re-Estize Kingdom for their own military. Further hinting to their future diplomatic relationship with the Sorcerer Kingdom.

On the other hand, the Sorcerer Kingdom also gained the extra benefits of being able to successfully train the Floor Guardians of the Great Tomb of Nazarick in war, strategy, conquest, and preparing massive/large scale invasions they can use as references for future wars and battles for the Sorcerer Kingdom. As seen where several of the Floor Guardians successfully conducted several experiments via trial and error to create various unique invasion strategies using their current resources. As seen where Shalltear Bloodfallen, who had successfully created a highly effective invasion strategy that takes full advantage of her transport network of using their conquered Frost Dragons to air carry their Soul Eaters to bombard and annihilate entire cities and towns. Meanwhile, Mare Bello Fiore successfully gained experience on how to destroy large scale cities, residential areas and places of dwelling using his magic cleanly and effectively to massacre all of its inhabitants in mass. And both Demiurge and Albedo successfully obtained further political, espionage, and wide scale information manipulation experience for future operations. As for Cocytus, he obtained first hand experience on how to launch and lead a large scale invasion force.

Additionally the Sorcerer Kingdom had also obtained its first credible information on the Natural Magics present in the New World thanks to the interloper Riku Agnia's assassination attempt on their Monarch, who made excessive use of Wild Magic during his duel against "Ainz Ooal Gown" and additionally the higher ops of the Sorcerer Kingdom also obtained information on the Adamantite Adventurer of Red Drop, Azuth Aindra due to his battle against Albedo and him making excessive use of his Armor of Reinforcement. In addition to obtaining the solid information on Wild Magic, the Sorcerer Kingdom had also successfully given the interlopers a false estimate of the "Sorcerer King's" power level and overall abilities that effectively rendered them overconfident as a future advantage in Riku's future assassination attempts.

Now that their fallen enemies' former territory was now the Sorcerer Kingdom's for the taking, they have done so with extreme swiftness. Renner is transformed into a demon and joined the ranks of Nazarick and manipulated Climb to do the same after his resurrection; adding the tactical genius and leadership skills of the former third princess to Nazarick's collection of valuable assets. Nazarick also claimed many useful items during their onslaught such as the legendary magic sword Razor Edge and the recently re-acquired prototype of Armageddon Evil.

Ironically, the New Faction ended up being correct in their assumption: the Sorcerer Kingdom lacked the manpower to conquer the Kingdom, so they destroyed the nation instead.

Trivia

 * Despite opportunities to escape, the overwhelming majority of Re-Estize Kingdom's citizens chose to remain in the doomed country since they possessed neither resources, connections nor skills to help them survive in the foreign lands.