Hephaestus is the son of Zeus and Hera, even though Zeus had nothing to do with it. Hephaestus was conceived without male fertilization. Hera became jealous of Zeus after he had an affair with Metis, which became pregnant with Athena. He had been warned by Gaia that Metis would bear a daughter whose son would eventually overthrow him. In fear, Zeus ate Metis whole so he could give birh to the child himself. In revenge, Hera produced Hephaestus that split the head of his father with an axe, thus producing Athena whom which was fully armed with armor.
