The Four Nations are a confederacy of loosely connected kingdoms on the continent of Naipan. Among these nations are the Water Tribes , the Earth Kingdom , the Fire Nation , and the Air Nomads . These kingdoms are all ruled independantly. The Earth and Fire nations are ruled by a daimyo, while the Water Tribes and Air Nomads have no central rulership.
There was a time when the Four Nations were ruled over by the Jade Emperor who ruled from a palace high atop the Five Elements Mountain. Since the emperor's disappearance five hundred years ago, the nations have long since splintered.
Each of the nations have their own systems of government, cultural details and histories, though they share many things in common. Though they are separated by many differences, they are all one people, descended from the same ancient ancestors, and so share many physical features, including dark hair and almond shaped eyes.