of their caves. These works have been dated to between 16,000 and 25,000 BC. As early as the 15th century BC the citizens of Sidon and Tyre, two cities on the coast of Ancient Phoenicia (present day Lebanon), were producing purple dye from a sea snail called the spiny dye-murex. Clothing colored with the Tyrian dye was mentioned in both the Iliad of Homer and the Aeneid of Virgil. The deep, rich purple dye made from this snail became known as Tyrian purple. The process of making the dye was long, difficult and expensive. Thousands of the tiny snails had to be found, their shells cracked, the snail removed. Mountains of empty shells have been found at the ancient sites of Sidon and Tyre. The snails were left to soak, then a tiny gland was removed and the juice extracted and put in a basin, which was placed in the sunlight. There, a remarkable transformation took place. In the sunlight the juice turned white, then yellow-green, then green, then violet, then a red which turned darker and darker. The process had to be stopped at exactly the right time to obtain the desired color, which could range from a bright crimson to a dark purple, the color of dried blood. Then either wool, linen or silk would be dyed. The exact hue varied between crimson and violet, but it was always rich, bright and lasting. Tyrian purple became the color of kings, nobles, priests and magistrates all around the Mediterranean. It was mentioned in the Hebrew Bible (Old Testament); in the Book of Exodus, God instructs Moses to have the Israelites bring him an offering including cloth "of blue, and purple, and scarlet," to be used in the curtains of the Tabernacle and the garments of priests. The term used for purple in the 4th-century Latin Vulgate version of the Bible passage is purpura or Tyrian purple. In the Iliad of Homer, the belt of Ajax is purple, and the tails of the horses of Trojan warriors are dipped in purple. In the Odyssey, the blankets on the wedding bed of Odysseus are purple. In the poems of Sappho (6th century BC) she celebrates the skill of the dyers of the Greek kingdom of Lydia who made purple footwear, and in the play of Aeschylus (525–456 BC), Queen Clytemnestra welcomes back her husband Agamemnon by decorating the palace with purple