Shea comments that the ram represented both the kings of Media and Persia who were intermarried and living on the Iranian plateau. The smaller group, Persians, lived to the south and the stronger and larger group of Medes lived in the north. In the sixth century BC the up and coming king, Cyrus, succeeded in conquering the Medes, fusing them into a combined Media-Persia empire. Cyrus lead both parties in 547 BC to the North to conquer Lydia in ancient Turkey. He then conquered Babylon to the West in 539 BC. After a reign of 7 years, Cyrus left the kingdom to his son Cambyses, who reigned 7 years 5 months. To the South, Cambyses conquered Egypt in 525 BC. Under Darius the Great and Xerxes the Persian empire attempted to conquer Greece, but the Greeks defeated them at Marathon (490 BC), Salamis (480 BC) and Platea (479 BC).   Darius Codomannus was the last of the Persian kings. It was his misfortune to contend with another great historical figure — Alexander the Great. The deciding point was reached during the Battle of Gaugamela in 331 BC where the Grecians, though outnumbered 20 to 1 against one million men, won a decisive victory. Alexander became absolute lord of the Persian Empire.