The correlation between the Medes and Persians before the foundation of Achaemenid Empire

The Medes and Persians were two close ethnic Immigrant Aryan ethic groups who immigrated to Iranian plateau probably in the second half of the second millennium BC and settled in the East of Zagrous mountain range. The presence of various ethnic groups in this region and the Assyrians in specific frequently campaigned against the new comers. The Medes and Persians had to unite with some of these groups; so the Medes joined the Diaku and the Persians، the Achaemenes. Objective of this article is the examining the correlation between the Medes and Persians before the Achaemenid Empire was established. Although many of scholars of ancient history، based on Herodotus reports indicate that Medes ruled over the Persians after Phraortes، in this article it is tried to demonstrate the opposite. Based on the Greek Historians reports and Mesopotamia documents، in particular Assyrian، Babylonian and Archaeological data، and applying historical methodology these two Aryan groups lived peacefully before Astyages who for the first time took campaign against Cyrus the Great in 559 BC. In other words، it was Astyages، who for the first time tried to overcome Persia where Arian ethic groups lived in peace with mutual respect towards one another.