The War of Air and Fire

Background
During the Age of Blood, many gods retreated from Rojopotis and built fortresses in the four elemental planes. These groupings gradually turned into alliances, known as the four houses. The House of Air and the House of Fire each sought control of Rojopotis, and a great war ensued, the War of Air and Fire.

The War
All mortal race - namely giants, dragons, elves, dwarves, and humans - were enlisted to fight in the war. The war lasted generations, and spanned many material planes. Ultimately the House of Air was victorious, and the plane of fire was sealed off with the gods of the House of Fire trapped inside.

Aftermath
The victorious House of Air called a council of gods in Arcadia. There they decided how the material planes would be oriented, created the Underdark to imprison those that fought for Fire, created the Feywild so the Seelie Court would leave Rojopotis, and redesigned Rojopotis to be 1/2 air, 1/4 water, and 1/4 earth. Fire was banished from the material planes.