Cyrus II or Cyrus the Great (ca.600 - 530 BC) was a towering figure in ancient world history. As the "father of the Iranian nation", he is considered the first world leader to be referred to as "The Great". Cyrus founded the first world empire and the second Iranian dynastic empire (the Achaemenids). After defeating the Median dynasty and uniting the Medes with the other major Iranian tribe, the Persians under King Cyrus controlled an enormous amount of land.

As the founder of the Achaemenid Empire, one of Cyrus' goals was to gain power over the Mediterranean coast and secure Asia Minor. Croesus of Lydia, Nabonidus of Babylonia and Amasis II of Egypt joined in alliance with Sparta in an effort to stop Cyrus. The alliance did not work.

Hyrcania, Parthia and Armenia were part of the Median Kingdom. So, Cyrus moved further east to annex Drangiana, Arachosia, Margiana, and Bactria to his territories. After crossing the Oxus, he reached the Jaxartes. There, he built fortified towns. They could defend the farthest frontier of the Empire against Iranian nomadic tribes of Central Asia such as the Scythians. The exact limits of Cyrus' eastern conquests are not known, but it is possible that they extended as far as the Peshawar region in modern Pakistan.

Next, he looked west and invaded Babylon. He was very successful. He became: "King of Babylon, King of Sumer, and Akkad, King of the four corners of the world". All of his conquests triggered a true age of Empire Building.

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