Athena is the daughter of Metis and Zeus. Metis is one of the many Oceanids and the first wife of Zeus. While pregnant with her daughter Athena, Zeus swallowed Metis whole. He did this under the advice of Gaia and Uranus, for fear that Metis would have a child more powerful than himself. This is because she was fated to have a clever daughter, Athena, and then a son, who would one day overthrow Zeus. In this way, Zeus prevented Metis from every giving birth to a son. Plus, with her now in his stomach, Zeus could now receive sound advice from both his mind and his belly. When Athena was born, Zeus began to experience a terrible headache. Metis was hammering away inside, making armor for her new child, Athena. Hephaestus was brought in to help the ailing god. Being a god of the forge and not medicine, Hephaestus resolved the situation by taking an axe to Zeus' head. From the gash, Athena sprung out, leaving her mother in his belly. Athena became the favorite daughter of Zeus.
The gray-eyed Athena is associated with warfare and wisdom. She is usually accompanied by Nike (victory). Athena is also known by the name of Pallas Athena and Tritogenia (three-birthed). The origins of both names are unclear, at least to me. Athena is typically portrayed in arms, a shield or breastplate (the aegis), a helmet and spear.
Athena is very closely connected with Athens. The chief temple on the Acropolis was dedicated to her. When the early Athenians were deciding upon a name, two gods vied for the town to be named after them. The gods were Poseidon and Athena. Poseidon gave the citizens the horse or a spring of sea water, and Athena gave them the olive. The Athenians of course chose the olive.
She was instrumental in helping Perseus kill Medusa, whom she had earlier turned into a Gorgon. After returning home, Perseus gave her the the head of Medusa, which Athena fixed upon her shield, called the aegis.
To aid the Argonauts on their quest, she fitted their boat, the Argo, with a special talking prow.
In the Trojan War, Athena was firmly on the side of the Greeks, due to the judgment of Paris for the golden apple. She prevented Achilles from engaging in combat with Agamemnon. When Ajax attacked the Greek camp, she sent a madness upon him. She also aided Odysseus on the journey home.
The Romans identified Athena with their Minerva, an important goddess of the crafts and warfare.