Before the Universal War, Rayuba was a peaceful, prosperous world. The famous martial artist, Musko Reeve, described Rayuba as "remarkably pretty" in his martial arts compendium, the Manual of Hands and Feet. The Rayuban military, called the Rayuban Home Guard, may have operated on a system similar to Sparta, as Solomon David is mentioned to have originally been a "citizen-soldier" who owned a sizeable homestead. The world gave home to the Monks of the Silent Voice, a monastic order of peaceful warrior-monks who were the masters of Ki Rata, the most powerful style of martial arts in existence.
During the Universal War, the demiurge Yemmod besieged Rayuba with his armies, and laid complete waste to it. The population was killed, and everything valuable was extracted from the world, leaving it a barren husk. Solomon David, who was trained in Ki Rata by the Monks of the Silent Voice during Rayuba's destruction, killed Yemmod and seized his Key for himself, becoming a demiurge. He then joined the Universal War in an effort to carve out his own empire.
There are two suns in Rayuba - Solomon claims to have put these in the sky by himself, to replace the world's original, single sun, which was destroyed by Yemmod's armies.