Craig Carter was an archaeologist, who wanted to some action to his life. He wanted to become a crime fighter. His wish was granted, when he received a ring from the mail. It was sent by Sau-Aben Toumau (whom Carter had saved in Egypt from something) as a thank you-gift. The letter that came with the ring, didn`t explain what the ring can do. But there did read, that "It will make you greater than any living mortal". What a way to than someone!
Later, when Craig tried to figure out how to fight crime, he found out what the ring can do. It can summon the Greek gods, when it is rubbed! Better yet, they will grant the wishes of the wearer of the ring, for some reason!
Naturally, Carter used the ring for fighting against crime, in both of his (currently) only appearances.