Persian troops took over the territories of the neighboring Medes and they began to dismantle the century old Babylonian Empire under the brilliant leadership of Cyrus the Great, thereby initiating two centuries of Persian rule in the course of 6th Century B. C. The lion like infantry troops of Persia conquered the entire Southwest Asia, the entire Central Asia, the entire territories of Egypt, the entire Levant, and even parts of Greece. The most skilled and brave Persian infantry came to be known as the immortals. The greatly formidable Persian Empire became significantly weakened during course of numerous total wars and it was at last conquered by Alexander the Great, the genius king of Macedonia.