Beginning with Alexander, Greek civilization stepped out into a new age. Greece was no longer living for herself, she was living for the world. Greek civilization had been far-flung over Asia; the Barbarian was adopting Greek customs, Greece was the teacher of the world, in science, in art, and in all that was meant by civilized living. This period lasted from the time of Alexander until Greece became part of the Roman Empire in 146 B.C., and is known as the _Hellenistic Age_. The centre of Greek civilization was now no longer in Athens, but in Alexandria, the city in Egypt founded by Alexander, and which from its situation was the natural link between the East and the West. {400} II. ALEXANDRIA Alexandria had not been founded for very many years before she was the rival of Carthage, that powerful commercial city founded by the Phoenicians, as mistress of the Mediterranean, and in the Eastern Mediterranean, known as the Levant, she held undisputed sway. From that time to the present day Alexandria has been the door through which the commerce of the East and the West has passed. In the Hellenistic Age, Alexandria developed into a very beautiful city. Temples and all kinds of public buildings, great palaces and gardens, docks and warehouses were built. At the entrance to the harbour stood a great lighthouse, called the Pharos from the island on which it stood, and which was considered so great a marvel that it was numbered amongst the Seven Wonders of the ancient World.