Achaemenid Empire

The Achaemenid Empire (/əˈkiːmənɪd/; Old Persian: 𐎧𐏁𐏂, romanized: Xšāça, lit. ’The Empire’), also called the First Persian Empire,[15] was an ancient Iranian empire that was based in Western Asia and founded by Cyrus the Great in 550 BC. It reached its greatest extent under Xerxes I, who conquered most of northern and central ancient Greece. At its greatest territorial extent, the Achaemenid Empire stretched from the Balkans and Eastern Europe in the west to the Indus Valley in the east. The empire was larger than any previous empire in history, spanning a total of 5.5 million square kilometers (2.1 million square miles).[11][12]

The empire had its beginnings in the 7th century BC, when the Persians settled in the southwestern portion of the Iranian Plateau, in the region of Persis.[16] From this region, Cyrus rose and defeated the Median Empire—of which he had previously been king—as well as Lydia and the Neo-Babylonian Empire, following which he formally established the Achaemenid Empire.