The Eternal War
There are four Islands, one representing the elements: Fire, Ice, Water, and Air. These islands each contain one city, which are shared by the Genasi and Dragonborn of those types. As the two races share cities, there is some stress among the clans of each race, and low scale skirmishes erupt. On the Isla del Fuego and the Isla del Hielo, the Dragonborn have risen to rule those cities. On the Island of Air and the Island of Water, the Genasi have risen to control the cities.