Some say Athene had a father named Pallas, a winged goatish giant. After he attempted to outrage her, she made the aegis from his skin, put his wings on her own shoulders and added his name to hers. If the aegis isn't the skin of Medusa.
Others say her father was Itonus, king of Iton, whose daughter she killed by showing her the Gorgon's head. Still others say Poseidon was her father, but she disowned him and asked Zeus to adopt her.
But Athene's own priests tell the following story: Zeus lusted after the Titaness Metis and, though she changed into many shapes, caught her. An oracle predicted she would bear a girl-child and if Metis conceived again, this son would depose Zeus - like Zeus had done to Cronus and Cronus to Uranus. Zeus swallowed Metis, but soon he got a headache.
Hermes figured out the cause and a hole was drilled in Zeus' skull. Out sprang Athene, fully armed, with a mighty shout.
Robert Graves, The Greek Myths. Complete Edition.