Emperor-Beyond-The-Sea

Not appearing at all, and rarely being mentioned, the  Emperor-Over-The-Sea, according to folklore, is said to be the father of Aslan, whose divinity was present before the creation of Narnia. Presumably, he created the laws that govern Narnia.

Trivia

 * The Emperor-Over-The-Sea is said to represent God. In turn, God is the father of Jesus Christ, whom is said to Aslan represents.
 * The Emperor is only mentioned in The Lion, the Witch and the Wardrobe, Prince Caspian, and The Horse and His Boy. In later novels, his attributes are embodied in Aslan. Whether or not this change was deliberate on Lewis' part, his status is unclear by the end of The Last Battle.
 * The Emperor-Over-The-Sea is yet to be mentioned in any film adaptations.