Around 1,000 years prior to the events of Tales of Destiny, a Lens-infused comet collided with the planet, producing massive amounts of dust that clouded the atmosphere. This event led to an ice age that threatened humankind until humans were able to use the Lens from the comet to create a floating continent known as the Aethersphere. Only the upper class was allowed to migrate to the continent, however, which caused intense strife and eventually led to a conflict known as the Aeth'er Wars. It was during this time that the people of the Aethersphere became known as the Aeth'er race, while those left behind came to be known as the Er'ther race. While no physical anomalies arose between the two populaces, labeling the groups as races allowed for a stronger distinction, as the elitism of the Aetherian people had grown severe.
Kronos, a powerful Aetherian king, ruled over the Aethersphere and used the mysterious Eye of Atamoni to construct the landmass, which threatened to cover the Er'ther Lands, eradicating its population in the process. The Er'ther people lived in fear because of this, and any hope of rebellion was shattered by the impending danger of Belcrant, a massive, sword-shaped superweapon the Aetherians used to strike down all who opposed them. Eventually, the Er'ther people were aided by a group of Aetherian scientists who had grown disgusted with their people's elitist behavior and descended to the surface world. One of these scientists, Harold Berselius, created sentient swords known as Swordians, which a team of combatants, later called Swordian Masters, used to infiltrate Dycroft and defeat Kronos, ending the war.
Afterward, the Er'ther people sunk the Aethersphere and its aerial cities into the depths of the ocean and exiled the survivors of the Aeth'er race to the harsh region of Calvalese. In modern times, these events have long been forgotten by the current populace, though the descendants of the Er'ther people comprise a vast majority of the population, while the descendants of the Aetherians are restricted to Calvalese and remain hostile toward outsiders. "Er'ther Lands" is a term used to refer to the unnamed planet, as the Er'ther people's actions marked 1,000 years of historical advancement. Nations, governments, and rulers are all the results of Er'ther achievements, while Aetherian culture has been limited to religion.