Iris Keeper of the Rainbow Throughout the ages, the rainbow has been the symbol of hope, a promise of better things to come.The ancient Greeks personified the rainbow as the goddess Iris, the favorite handmaiden and messenger of Hera, the queen of the heavenly court of Olympus. Carried by her shimmering wings, Iris travels so swiftly that mortals can see only the trail of her rainbow-colored passage across the sky.