Zeus, the god of all gods, made Metis, goddess of prudence, his wife. Gaea prophesied that Metis’ first offspring would be a girl and her second child would be a boy; a boy that would end up deposing Zeus— just like Zeus had taken power from Cronus. He took the warning to heart. When Metis was pregnant with Athena, Zeus, much like his father’s deed, took the precaution of swallowing Metis with her unborn child. This sparked Metis’ end. Eventually, Zeus started to sustain an insufferable headache, making him scream so stridently— enough to be heard far and wide on earth. To see what the problem was, the other gods quickly rallied. The god Hermes knew what had to be done and told Hephaestus to crack Zeus’ scull open with a wedge. Hephaestus did just that and out of Zeus’ scull emerged the fully grown Athena, equipped with armor. The preemptive measure Zeus took to swallow his wife and unborn child was futile, as it was Hera who gave birth to a son that pursued him. And this was Hephaestus— the one who ended Zeus’ miserable headache by splitting his head open - from which Athena was born.
Mythology and Theology: Greek Narrative of Love Affairs of Zeus
