Our protagonist, the prince of Altea and a successor to Anri, the hero who vanquished the Shadow Dragon Medeus. After Marth's homeland is destroyed by the imperial forces of Dolhr, he and a small retinue of subjects are forced into hiding in the kingdom of Talys. He then rises up to save the continent, gaining new comrades on the battlefield as he faces the Dolhr Empire.

The prince of Altea who brought the War of Shadows to a close by using the blade Falchion—the Altean royal family's divine heirloom—to seal away the war's instigator, the Shadow Dragon Medeus. After the war, while working diligently to rebuild his kingdom, Marth is tasked by Hardin, the new emperor of Archanea, to quell a rebellion in Grust.