Battle of Castour Field

The Battle of Castour Field (カスツール平原の戦い) was a decisive encounter that took place during the early stages of the Demi-Human War. Occurring approximately 46 years before Natsuki Subaru's arrival in the Kingdom of Lugunica and two years after the start of the war, a detachment of the Lugunican Royal Army was ambushed and routed by the forces of the Demi-Human Alliance under Valga Cromwell.

Using a small unit of demi-human soldiers as bait, Cromwell was able to lure the Lugunican troops onto a field covered in magic circles that when activated tore up the human battle formations. In the confusion and chaos, the demi-human forces were able to advance and surround the enemy. Though the encirclement operation was a flawless success, the Demi-Human Alliance took considerable losses when a lone soldier named Wilhelm Trias broke through the front line, temporarily blunting the surprise attack.

Though both sides took high numbers of casualties, the battle was a victory for rebel forces. A major embarrassment for the Lugunican military, the battle lead to the reorganization of the Royal Army and the implementation of a new military doctrine with the emphasis on countering magic circles, an idea that would ironically lead to the loss during a later battle.^[1] The battle also contributed to the growing reputation of the young Wilhelm Trias, who gained the nickname of "Sword Demon" from a fellow survivor in reference to his actions on the field.^[2]

Background

Before the clash at Castour Field, the earlier Battle of Redonas Plateau taking place just days earlier foreshadowed the coming events, where an overextended human army had been engaged with by demi-human forces utilizing magic and suffered an abundance of casualties despite winning in the end. The battle was the debut of the 15-year-old swordsman Wilhelm Trias.^[3] As the next military expedition into Castour Field was quickly approaching, the Lugunican military had little time to adjust to the new apparent bait-and-break strategy of the demi-human commander Valga Cromwell.

Battle

Days after the Battle of Redonas Plateau, the humans continued their advance into enemy territory. Suddenly facing a sizable force of rebels in their path, the Royal Army halted their march and immediately began to prepare for battle. The armies began engaging at sunset,^[4] with the renowned Zergev Squadron, led by Bordeaux Zergev at the very front.^[5] With shock, numbers, and momentum, the humans slammed directly into the demi-human troops, completely rupturing the frontline.

As the battle progressed, Wilhelm broke through a demi-human encirclement and killed 88 members of a demi-human squadron, including the captain.^[6] Facing mounting casualties and overwhelming numbers, the demi-humans appeared to rout. Despite this, both Wilhelm and Grimm Fauzen, the latter of which was shielding his ally as he fired off his arrows, each had a bad feeling about how simple the battle was when compared to the one just days prior.

Cromwell's Ambush

Unbeknownst to the human forces, they had been lured into a massive trap set in place by the backbone of the Demi-Human Alliance, Sphinx. Just as the Lugunican army had appeared victorious, the wide field of magic circles became active. The shaking of the ground quickly threw many soldiers to the ground. The humans, who had unintentionally walked themselves into a giant magical minefield, began to panic. The whole offensive contingent was immediately made combat ineffective. Right on cue was the larger demi-human counterattack force, who came barreling through the dust and the smoke to surround the disorganized Lugunican army. As usual, Wilhelm Trias committed to his own breakthrough, even as the majority of the soldiers implored him to retreat. Suspecting the genocidal intent of demi-human commander Cromwell, Wilhelm correctly assumed the battle plan of the Demi-Human Alliance, which was to slaughter the retreating Lugunican soldiers after breaking up their front lines with a sudden assault.^[7]

Realizing that his enemies were intending for the army to retreat, Wilhelm charged into the heart of the demi-human assault while the others, in chaos fell to retreat, ignoring the warning that Wilhelm gave them. Despite his fears, Grimm chased after him to bring him back, claiming that the army still needed him alive. Along the way, he found the lines of a magic circle and damaged it out of fear. Wilhelm, who appeared and explained the entire trap, proceeded to kill a demi-human ambusher, and despite Grimm's protests to bring him back, Wilhelm told him that he could either retreat and die or push on and live, and then he set off to continue battling. Left to make a decision, Grimm chased after him, feeling less fear by moving forward than back, and after catching up to Wilhelm and witnessing his smile as he slaughtered his enemies, he coined him as a Sword Demon. Soon after, Valga's trap went off, causing many casualties for the Royal Army and resulting in the Demi-Human Alliance's victory. Soon after, the main force of the Royal Army arrived and rescued what remained of the contingent.

Aftermath

The battle was a major defeat for the Lugunican military, which was forced to reconsider their entire strategy. Compared to the Battle of Redonas Plateau, where the humans also suffered major casualties, the battle at Castour lacked the victory of Redonas.^[8] In accordance with new doctrine, the magical specialist Roswaal J. Mathers was brought in to inspect the magic circles. From then on, the military placed magic circle elimination as a priority before entering a battle.

Out of their hundred in their squadron, Wilhelm Trias and Grimm Fauzen were the only two survivors left.^[9] Most of the unit formations were wiped out in the initial ambush or were killed in the rout. Everyone in the Zergev Squadron returned alive.^[10] As news of Wilhelm's violent and heroic actions spread around the country, the name of "Sword Demon" became associated with death and blood.^[11]

For the demi-humans, the battle was a complete success. In the eyes of the Valga Cromwell, the death of so many humans would bring him pride and inspire him to intensify the war. Conversely, commander Libre Fermi was overall furious at the deadly strategy and criticized Valga's ruthless need to kill humans. Furthermore, he warned Cromwell that the massive number of casualties would only drive the humans to escalate the war.^[12] In the end, Valga only resolved to kill every single human and plotted with Sphinx for the upcoming battles.

References