Sharing a common Aryan ancestry (tribal people from contemporary Russia), the Medes migrated to occupy
contemporary western Iran south of the Caspian Sea (northern Iran), and the Persians settled in contemporary
southwest Iran towards the Persian Gulf (southern Iran).
The Assyrians (based in contemporary Iraq), dominating the Middle East during 900-612 B.C., began to lose
power at the edges of their empire. To the north, the Scythians (contemporary lower Russia around the Caucasus
mountain range) began to assert their dominance of northwest Iran. To the south, Nabopolassar, Nebuchadnezzar’s
father, began to assert his authority in Babylon against the Assyrians.
By 625 B.C., the Medes led by Cyaxares (ruled 625-585 B.C.) united Iran and established control over northern
Mesopotamia. The Medes’ southwestern expansion was checked by the rising power of the Babylonians, and in an
alliance together, Babylon overthrew the Assyrians with the capture of of Nineveh in 612 B.C. The Assyrians would
attempt to contest with an alliance with Egypt but would lose their empire with the loss of their last fortified
city Carchemish in 605 B.C.
Cyaxares installed Cambyses I (ruled 580-559 B.C.) to manage a region called Anshan (Persia), and when Cyaxares
died in 585 B.C., his son Astyages (ruled 585-550 B.C.) ascended to the throne. To maintain an alliance with the
Persians, Astyages gave his daughter Mandane to Cambyses I who fathered Cyrus II of Persia (Cyrus the Great); thus,
Cyrus the Great had a Persian father and a Median mother.
When Cyrus the Great begins his conquest by first taking Media and capturing his grandfather king Astyages, it
is the beginning of the First Persian Empire. It would be known as the Achaemenid Empire and, by 480 B.C., become
one of the largest empires in history encompassing upwards of 50 million people.