Cyrus the Great (c. 600 BC or 576 BC – December 530 BC), also known as Cyrus II or Cyrus of Persia, was the first Zoroastrian Persian emperor. He was the founder of the Persian Empire under the Achaemenid dynasty.
It was under his own rule that the empire embraced all previous civilized states of the ancient Near East, expanded vastly and eventually conquered most of Southwest Asia and much of Central Asia, from Egypt and the Hellespont in the west to the Indus River in the east, to create the largest empire the world had yet seen.
The reign of Cyrus lasted 29 to 31 years. Cyrus built his empire by fighting and conquering first the Median Empire, then the Lydian Empire and the Neo-Babylonian Empire. Either before or after Babylon, he led an expedition into central Asia, which resulted in major campaigns that brought "into subjection every nation without exception." Cyrus did not venture into Egypt, as he himself died in battle, fighting the Massagetae along the Syr Darya in December 530 BC. He was succeeded by his son, Cambyses II, who managed to add to the empire by conquering Egypt, Nubia, and Cyrenaica during his short rule.
As a military leader, Cyrus left a legacy on the art of leadership and decision making, and he attributed his success to "Diversity in counsel, unity in command." Cyrus the Great respected the customs and religions of the lands he conquered. It is said that in universal history, the role of the Achaemenid empire founded by Cyrus lies in its very successful model for centralized administration and establishing a government working to the advantage and profit of its subjects. In fact, the administration of the empire through satraps and the vital principle of forming a government at Pasargadae were the work of Cyrus. Aside from his own nation, Iran, Cyrus also left a lasting legacy on Jewish religion (through his Edict of Restoration), human rights, politics, and military strategy, as well as on both Eastern and Western civilizations.