Leo the Lion, 13th century artwork. The spots show the position of the stars that make up this constellation, one of the twelve star signs of the zodiac. The Sun passes through these star signs in the course of the year, so they are considered to be significant in astrology, the ancient belief that the heavenly bodies influence human lives. The shape of the constellations inspired the names that were given to them. This artwork is from Le Livres des Etoiles (The Book of Stars), published in Sicily, Italy, in the 13th century. This copy is from the Arsenal Library, Paris, France. The book is a Latin translation of the Arabic Book of Fixed Stars by As Sufi, published in 964.