King Cyrus defeated the Medes (who ruled the Persians around 700 B.C.) in 550 B.C. He then captured Babylonia in 539 B.C. His empire stretched all the way to the Aegean Sea, including Mesopotamia. King Cyrus, the Great, was successful because he was tolerant of other peoples beliefs and practices. Upon winning a war, he expanded his empire by allowing conquered kings to keep their crown, but required them to pay a tribute, or tax. He also allowed these conquered peoples the freedom to follow their own customs and religions. People respected his rule because he was tolerant.

Persian leaders conquered many lands in what is known today as the Middle East. They captured the Babylonian Empire. They captured Mesopotamia. Persian rulers ruled for 200 years.  This reign experienced peace and prosperity. Wise leadership created diversity and tolerance. Many different cultures were united under Persian rule.

Cyrus' son (Cambyses) ruled after his death. Cambyses added Egypt and Lybia to its empire. Then, Darius I came into power and ruled Persia at its height. Darius I expanded the empire (2,800 miles) from India to southeastern Europe. Darius I was wise, like Cyrus, the Great. He divided the empire into more manageable districts, or provinces. His governors, called Satraps, ruled the provinces. He taxed provinces only half of what they could afford to pay. He started a form of money to make it easier to pay taxes.  

Darius I had roads built to ensure that communication and trade was made easier. He had the Royal Road built (1,500 miles long). Roads connected all 20 provinces. These roads unified the peoples of Persia. Darius I also had the new capital city (Persepolis) built. It had jeweled statues and other luxurious decorations. Persepolis was built to exemplify the greatness of the Persian Empire.  The Persian Empire was the largest and most stable (and powerful) empire in ancient Mesopotamia.