Uranus, which was discovered by William Herschel in 1781, was unknown in ancient times. Astronomers continued the practice of naming planets after deities in Greek and Roman mythology and named this new planet after the Greek god Ouranos (Roman Caelus). Ouranos was the son and husband of Gaea and the first god of the sky, or heavens. His father is sometimes said to have been Aether (Air). He was the father of the Titans, the Cyclopes, the Hecatonchires, the Erinyes, and the Gigantes, the Meliae, and Aphrodite. He was horrified by his eldest children, and locked them up inside the Earth. But this caused Gaea a great deal of pain, and she convinced her Titan sons to fight their father. Kronos (Saturn) - one of the Titans - castrated Ouranos with a sickle, and his blood caused the birth of the Erinyes and the Gigantes. We don't have art that shows Ouranos, but this image of a Roman mosaic from a villa in Italy does show his wife, Gaea, with the Anatolian god Aion, who was identified with both Kronos and Ouranos, and her children.