Every Campaign Needs a Cool Name
In the beginning, there was stuff, and it existed.
The races of the realm arose individually within Linmore. They grew into very distinct nationalities, with their racial heritage strongly representing each one. It took a threat of pure evil to cause the races to come together as one. Shamans predicted the apocalyptic event, as the skies fiery tears foretold of the devastation to come (though astronomers millenniums later would realize that these events were unrelated, as the planet had just happened to pass through the remnants of asteroid collisions in the Blooper Belt that slowly drifted into the orbit of the planet. Rookie mistake shamans, rookie mistake).
The night skies began to be flitted with dark shapes skimming across the sky. They would swoop down, taking livestock and villagers away from the different cities. The Dwarven and Tiefling lands began to be occupied by dragons and drakes that would hoard their riches within the mountains. White dragons took over barbarian lands of The Cold North, living in underground caves, sending Dragonborn to refugee camps lining the icy border of their once sparse lands.
As more and more lands were poached and taken over, the races of the realm realized that drastic measures had to be taken. Each land selected a champion, their best warrior, and sent them to the battlefield. The elders of the lands realized that the dragons had a tendency to come from the central blasted lands, that were declared uninhabitable. As each party fought their way to the blasted lands, the dragons that were spread across the realm came flying back to their spawning grounds.