The project was initiated around the end of the second Imperial invasion of Gallia by the Asgardian Council, composed of Gilbert Gassenarl, Laurence Kluivert, and Clementia Förster. Clementia had originally worked at an Imperial Valkyria research facility but after the death of Prince Maximilian defected to Gallia to continue her work, bringing with her a Valkyria test subject named Aliasse. Whereas Clementia sought to create a perfect being without what she viewed as the weakness of humanity, Gilbert and Laurence were more motivated by a desire to protect their homeland should the Empire or Federation encroach upon Gallia once more. However, neither men had the approval of the Gallian government and were in fact violating the law in conducting the human experimentation needed to advance the project.
To this end, Laurence used his position as headmaster of the Lanseal Military Academy to scout for potential candidates to undergo the conversion into an Artificial Valkyria. Incoming students were screened and placed into different classes based on their aptitude for the procedure, with students in class A being deemed the most suitable while students in class G were ones whose evaluation was inconclusive. Two candidates were initially selected, the Darcsen Jugin and Leon Hardins, a promising cadet that had served with valor in the recent war with the Empire. Jugin was unable to muster the will to go through with the procedure and withdrew from the academy, leaving Leon as the sole candidate. While the procedure succeeded in granting Leon the powers of a Valkyria, his personality was shattered in the process and Leon became little more than an unthinking automaton.
After Leon's transformation into the V0 Artificial Valkyria, Gilbert founded the Gallian Revolutionary Army and initiated a rebellion against the Archduchess Cordelia. The Asgardian Council was disbanded, but the respective members continued their work. Gilbert took Leon with him and provided him with the alias of Dirk Gassenarl, claiming Leon as another son. Using what research he had taken with him, Gilbert also developed the V2 Artificial Valkyria system and put it into mass production, granting the GRA a considerable tactical advantage against conventional forces. Clementia continued to refine her work at Lanseal while Laurence searched for a new candidate to test on. He eventually found one in the chair of Class A, Juliana Everhart. The rebel assault on Lanseal forced Julianna to undergo the procedure to defend the academy. While Julianna bested several of the rebel V2's, she was mortally wounded engaging Leon. The rebels also took the opportunity to seize Clementia's research from her Lanseal lab during the assault.
Realizing the magnitude of the loss, Laurence confessed his actions when confronted by instructor Hubert Brixham and Leon's brother, Avan Hardins. Laurence however remained unrepentant, insisting that his actions were for the greater good. Laurence ultimately committed suicide rather than see his efforts be turned against Gallia by the rebels. With her patron dead and her research stolen, Clementia also made her exit. She was however forced to leave behind Aliasse, whom had grown attached to the Lanseal students and refused to abandon her new-found friends.
With the research seized from Lanseal, the rebels were able to create a considerably more refined Artificial Valkyria system. This system was only used once, by Baldren Gassenarl at his last stand aboard the battleship Dandarius. Lanseal forces were however able to destroy the power system Baldren carried on his back and fatally wounded the self-proclaimed archduke. With his dream ended, Baldren went down with the Dandarius. The destruction of the battleship also resulted in the destruction of all data associated with Project Valhalla, as the rebels had sought to escape to Federation territory with the project's fruits.