The Achaemenid Empire (c. 550-330 BCE), sometimes known as First Persian Empire, was an empire in Southwest Asia, founded in the 6th century BCE by Cyrus the Great who overthrew the Median confederation. It expanded to eventually rule over significant portions of the ancient world which at around 500 BCE stretched from the Indus Valley in the east, to Thrace and Macedon on the northeastern border of Greece making it the biggest empire the world had yet seen. The Achaemenid Empire would eventually control Egypt as well. It was ruled by a series of monarchs who unified its disparate tribes and nationalities
At the height of its power after the conquest of Egypt, the empire encompassed approximately 8 million km2 spanning three continents: Asia, Africa and Europe In 480 BCE, it is estimated that 50 million people lived in the Achaemenid Empire or about 44% of the world's population at the time, making it the largest ever empire by population in percentage terms.
Xerxes is portrayed in Greek histories as a weak monarch who launched an insane attack upon Greece. However, in Persian records he is presented quite differently. He is seen as a great administrator who brought progress to the empire. The truth would appear to be a combination of both these views. Undoubtedly, Xerxes’ greatest achievement as an administrator was the construction of the Persian capital, Persepolis. Though it was his father Darius who laid out the plans for the city, Xerxes himself oversaw most of the building.
Xerxes was also an able king politically – certainly for most of his career. Control of the empire was maintained by the 23 satraps, who ruled on Xerxes’ behalf. They were...