She came from the ageless void of nothingness and darkness called Chaos. From her Ouranos was born and from them, the Titans were born.
It was Gaia who encouraged Kronos to rebel against his father, providing him with a scythe forged of adamant, the strongest substance in existance, to castrate Ouranus while he and her were making love.
She rewarded Kronos with his father's throne, granting him domain over the Earth, time itself, and over mankind.
Gaia was called upon by Reah, who asked her to look after and protect her last child, Zeus, from his father, Kronos. Gaia agreed and raised Zeus as her own in a far away land among the world of man. Gaia and the Humans taught Zeus the arts of crafts and combat, training him for the day that he would free Humanity from his father's reign.