The Mercenary Fortress was built recently by Viktor. The fortress was built at the request of Anabelle to make sure the eastern portion of Muse Principality was adequately protected from Highland.

During the Dunan Unification War, this fortress came under attack by General Solon Jhee. The mercenaries successfully defeated the first wave, but Luca Blight ambushed the mercenaries during the second attack, resulting in their defeat.

The fortress was then under the Highland Army's control for a while until Luca Blight was defeated by the Allied Army. The fortress became the final battlefield for Kiba Windamier, who protected it as a decoy to lure Leon Silveberg out of Highland.