The constellations we recognize today were first mapped by the ancient Greeks, who arranged the stars into patterns for that purpose. In the third century BC Eratosthenes compiled a handbook of astral mythology in which the constellations were associated with figures from legend, and myths were provided to explain how each person, creature, or object came to be placed in the sky. Thus we can see Heracles killing the Dragon, and Perseus slaying the sea-monster to save Andromeda; Orion chases the seven maidens transformed by Zeus into the Pleiades, and Aries, the golden ram, is identified flying up to the heavens. This translation brings together the later summaries from Eratosthenes's lost handbook with a guide to astronomy compiled by Hyginus, librarian to Augustus. Together with Aratus's astronomical poem the Phaenomena, these texts provide a complete collection of Greek astral myths; imaginative and picturesque, they also offer an intriguing insight into ancient science and culture.