SINCE the dawn of history, the sky had been a mystery to human beings. It was directly related to the unknown, and consequently man related his different myths to different constellations of the sky. Last week we showed how the Ancient Egyptians linked their myth of Isis and Osiris to the constellations mainly in the middle of the sky around the Polar star. In this article we move to another rich civilisation in mythology which is the Greek civilisation. At the time of the Hellenistic civilisation, a lot of myths were created especially in the epics of the Iliad and the Odyssey. An example of one of these myths is the myth of Andromeda and Perseus; the story is represented in the sky by six constellations which are Andromeda, Perseus, Pegasus, Cepheus, Cassiopeia and Cetus Andromeda was the daughter of Cepheus and Cassiopeia, king and queen of the kingdom of Ethiopia. Her mother, Cassiopeia, bragged that she was more beautiful than the Nereids, the nymph-daughters of the sea god Nereus often seen accompanying Poseidon. To punish the Queen for her arrogance, Poseidon, brother of Zeus and god of the sea, sent the sea monster Cetus to ravage the coast of Ethiopia including the kingdom of the vain Queen. The desperate King Cepheus consulted the Oracle of Zeus who asserted that no respite will be found until the king sacrificed his virgin daughter Andromeda to the monster. She was chained naked to a rock on the coast of Jaffa. Perseus, on his way back from having slain the Gorgon Medusa, riding the winged horse Pigasus, found Andromeda and slew Cetus. He set her free and married her in spite of Andromeda's being previously promised to her uncle Phineus. At the wedding a quarrel took place between the rivals, and Phineus was turned into stone by the sight of the Gorgon's head. As the Ancient Egyptians did, the Greeks also linked their myths to the sky but with one difference; all those mentioned Greek myth characters are represented immortally in the sky as constellations carrying their names up until today in the modern sky maps, while the Ancient Egyptian names given to the constellations did not survive the ages. When such great civilisations connect their mythological thinking to the different stars and constellations in an attempt to decipher the mysteries of the universe, it should make us stop and think. Next week, we will touch on how the Arabs surveyed all the constellations and stars of the sky and demonstrated them in tables and fascinating drawings keeping the naming of the Greek civilisation. [email protected] Saleh is the Director of Egypt's Centre for Documentation of Culture and Natural Heritage.