Greece is considered the cradle of Western civilization, being the birthplace of democracy, Western philosophy, Western literature, historiography, political science, major scientific and mathematical principles, theatre and the Olympic Games. From the eighth century BC, the Greeks were organised into various independent city-states, known as poleis (singular polis), which spanned the Mediterranean and the Black Sea. Philip II of Macedon united most of present-day Greece in the fourth century BC, with his son Alexander the Great rapidly conquering much of the ancient world, from the eastern Mediterranean to the North Western parts of India. The subsequent Hellenistic period saw the height of Greek culture and influence in antiquity. Greece was annexed by Rome in the second century BC, becoming an integral part of the Roman Empire and its continuation, the Byzantine Empire, which was culturally and linguistically predominantly Greek.
By 500 BC, the Persian Empire controlled the Greek city states in Asia Minor and Macedonia. Attempts by some of the Greek city-states of Asia Minor to overthrow Persian rule failed, and Persia invaded the states of mainland Greece in 492 BC, but was forced to withdraw after a defeat at the Battle of Marathon in 490 BC. In response, the Greek city-states formed the Hellenic League in 481 BC, led by Sparta, which was the first historically recorded union of Greek states since the mythical union of the Trojan War. A second invasion by the Persians followed in 480 BC. Following decisive Greek victories in 480 and 479 BC at Salamis, Plataea, and Mycale, the Persians were forced to withdraw for a second time, marking their eventual withdrawal from all of their European territories. Led by Athens and Sparta, the Greek victories in the Greco-Persian Wars are considered a pivotal moment in world history, as the 50 years of peace that followed are known as the Golden Age of Athens, the seminal period of ancient Greek development that laid many of the foundations of Western civilization. 2b1af7f3a8