War of Cosmic Heavens

"Five years of war among the heavens. Five years of blood among the earth. Five nations united against the sky. Five Nations blank and destroyed. The three arose, and faced the sky alone. Mæorius, the Light Bringer, Vælerios, The Spear of Heaven, and Ætious, the Master of War. They walked alone towards death, and what remained of the world followed. They fought the cosmos, and emerged victorious. Five Nations brought from ruin. And Five Great Lords to lead them. For Ætious sired five during the war of the cosmic heavens, one for each year of blood. And when they grew, they led the lands of Lemo and Dusil. A Lord of Stone, of Stars, of Steel, of Sea, and of Skulls. The Five Great Lords, sons and daughters of Ætious, and their descendants, were true heroes, just as much as their father, and his comrades."-Morrigan Aurelianos, on the War of Cosmic Heavens
The War of Cosmic Heavens was A massive war fought between the mortal races of Farathia, specifically Leomoth and Duloris, their Divine allies, against the alien forces of the Astral Void.
By all accounts, mankind's resistance to their invaders ended in defeat, with the near complete subjugation of the entire continent. However, after five years of war, a grand rebellion, led by Majorian and his companions, Aetius and Valeria, rose up, united the continent, and fought back the invaders. The war was finally put to an end when ancient Arcanists, at the cost of their lives, used every bit of power they could muster to summon forth a massive mountain range, which skewered the invaders starships like spears. This mountain range now divides the continent in two, a divide which has only recently been overcome.
According to Morrigan Aurelianos, after the war, The Five Great Lords, children of Aetius, were responsible for rebuilding the twin continents, their bloodlines eventually diluting across the population.