Caldas was a duke of Altea (then part of Archanea) who led with General Ordwin the liberation army during the War of Liberation and later became the king of Archanea through marriage to Artemis after Medeus's defeat.
As a resentment for the persecution of the Manakete survivors of the dragonkin, Medeus and his Dolhr Empire engaged Archanea in a war of vengeance which would later be known as the War of Liberation. Following the extermination of the Archanea royal family save for Princess Artemis, who took refuge in the Altea region, one of the kingdom's dukes, Caldas, had come into possession of the Fire Emblem and rallied a liberation army at the capital along with General Ordwin; their army successfully challenged the forces of Dolhr while Anri, wielder of Falchion, eventually slew Medeus and brought an end to the war. Afterward, Artemis reluctantly married Caldas at the request of the Archanean people, and he became the new king, while Caldas's younger brother, Marlon, forged the plains north of the country to form the kingdom of Aurelis, a close ally of Archanea.