TV-Series
Description
Longueville functioned as Headmaster Osmond's secretary at Tristain Academy of Magic, managing administrative tasks behind a professional facade. This identity masked her true self as Matilda de Saxe-Gotha, a disgraced noble turned commoner who retained potent magical abilities. Her triangle-class earth affinity specialized in crafting formidable golems, earning her the thief alias "Fouquet of the Crumbling Earth."

Operating as Fouquet, she stole valuables from nobles, often leaving mocking messages, to support the Reconquista faction's goal of overthrowing Albion's monarchy. While at the academy, she gathered intelligence on the Staff of Destruction stored in the vault. She orchestrated its theft during the Familiar Exhibition, then accompanied Louise, Kirche, Tabitha, and Saito on the mission to capture Fouquet, only to reveal herself by seizing the recovered staff. Saito disabling her golem weapon led directly to her capture.

In the anime continuity, Fouquet escaped custody during the battle where Louise defeated Wardes. The light novels significantly expanded her story: after escaping, she resurfaced in Albion's Westwood village, delivering supplies and protection to Tiffania Westwood. Tiffania's father had been viceroy to Matilda's family, and Matilda developed a sisterly or maternal bond with her, hiding her criminal activities. A tense encounter occurred when Saito's group arrived at Tiffania's cottage, leading to a temporary truce for Tiffania's safety. Matilda later departed, warning Saito they would become enemies again.

Her allegiance to Reconquista continued as she traveled with Wardes (who survived in the novels). By Volume 19, Vittorio assigned them to retrieve Saito and Tiffania from the elves in the Sahara, with orders to kill them if necessary to transfer their Void magic. She appeared during the Romalia-Gallia conflict arc in later novels. Matilda's earth magic manifested through terrain manipulation and golem creation, though sufficiently powerful counter-magic could overwhelm her spells. Her motivations intertwined with providing for Tiffania and fulfilling Reconquista's objectives.

Key relationships defined her: she tolerated Osmond's inappropriate behavior to maintain her cover, rebuffed advances like Count Mott's, and showed genuine concern for Tiffania's wellbeing. Her dynamic with Saito shifted from adversarial to cautiously respectful during their Westwood meeting, though she acknowledged future conflicts.