Ouranos: From Greek mythology, is the son and husband of the god Gaia. He made the mistake of preventing children from being born; so Gaia conspired with her youngest son Cronos to castrate Ouranos while he was having sex with Gaia, using a sickle. As a result of the castration, Ouranos retreated to the sky. Gaia's children were free, and Cronos became the chief god until Zeus too over, according to Elizabeth Vandiver, Classics scholar and authority on Greek mythology and Greek tragedy including the Iliad, Odyssey, Aeneid, Homer, and Virgil. This definition is based on her course Classical Mythology from The Teaching Company.