From Persis, Cyrus rose and defeated the Median Empire as well as Lydia and the Neo-Babylonian Empire, marking the formal establishment of a new imperial polity under the Achaemenid dynasty. Īround the 7th century BC, the region of Persis in the southwestern portion of the Iranian plateau was settled by the Persians. Based in Western Asia, it was the largest empire the world had ever seen at its time, spanning a total of 5.5 million square kilometres (2.1 million square miles) from the Balkans and Egypt in the west to Central Asia and the Indus Valley in the east. The Achaemenid Empire or Achaemenian Empire, also known as the First Persian Empire ( / ə ˈ k iː m ə n ɪ d/ Old Persian: 𐎧𐏁𐏂, Xšāça, lit. 'The Empire' or 'The Kingdom' ) was the ancient Iranian empire founded by Cyrus the Great of the Achaemenid dynasty in 550 BC. ^ Official language and native language of the ruling class.
