The Four are the deities of Erthos. They represent the four elements. Each god has a foothold in Erthos; these footholds act as herald, messenger, warrior, etc., depending on the situation.

"You see, there are four lords that created the land. They are of Water, of Fire, of Earth, and of Air. Each of these Deities controls their element, and other elements that correspond with it. However, the deities are unable to walk among their creations, nor are they allowed to directly interfere with the lives of mortals. As such, each must appoint a mortal to hold their powers, and to help the people of their dear creation. These mortals are no-longer allowed to age, and are given longevity that is only interrupted by "Death by the Blade for War"."

- Excert from Mark Hayzz's Bio in High Fantasy