Philosophy emerged in ancient Greece in the 6th century BCE. The pre-Socratic era lasted about two centuries, during which the expanding Persian Achaemenid Empire was stretching to the west, while the Greeks were advancing in trade and sea routes, reaching Cyprus and Syria. The first pre-Socratics lived in Ionia, on the western coast of Anatolia. Persians conquered the towns of Ionia c. 540 BCE and Persian tyrants then ruled them. The Greeks revolted in 499 BCE, but ultimately were defeated in 494 BCE. Slowly but steadily Athens became the philosophical center of Greece by the middle of the fifth century. Athens was entering its Classical Era, with philosophers such as Socrates, Plato, and Aristotle, but the impact of the pre-Socratics continued.