Hephaestus was depicted as either the son of Zeus and Hera, or of Hera alone. In this version, his mother conceived him spontaneously to take revenge on her husband when he gave birth to Athena. That it is Hephaestus who in some versions facilitates the birth of Athena provides a further instance of mythological flexibility, as does the question of how Hephaestus became lame. Either Hera's horror at producing a disabled child led her to hurl him off Olympus, or it was the fall that caused the disability. Hephaestus' lameness marginalized him on Olympus, however much his fellow deities needed the gifts that he was uniquely qualified to provide. As well as equipping the gods with their various weapons and other attributes, he helped particular Olympians to get out of certain tricky situations.When, for example, Athena was stuck, fully developed, inside the head of Zeus, it was the ax blow of Hephaestus that released her. His skill at craft also enabled him to turn particular situations to his favor, as when his unfaithful wife, Aphrodite, found herself caught with her lover Ares in a net so fine that it looked invisible.
by Susan Deacy, 30 Second Mythology