Achaemenes and the Black Sea; Causes and results of the expansion of an empire

In the history of ancient Iran, the Achaemenes state had experience in governance and a long presence in the lands around the Black Sea. The Achaemenes, who formed one of the first empires in human history, extended their vast borders in the north, south, east, and west to form seas or great rivers and brought large parts of Asia to the Greeks through trade exchanges and political relations. The maritime policy of the Achaemenes was access to all the coasts of the Black Sea, which protected them from invasions by the northern tribes and at the same time challenged the Greeks through their domination of Asia Minor and the enjoyment of its economic sources. This policy continued throughout the Achaemenes era, whether through military campaigns or by sending Achaemenes troops or families to the states of Asia Minor, but also through trade and economic activities. In this descriptive and analytical study has been reviewed the reason and circumstance of presence of Achaemenes in the area of the Black Sea, by study of Achaemenes inscriptions and Hellenic works and also researches of contemporary historians. This study concludes that Achaemenes based on a precise plan and then due to successive developments and events, thought that the Black Sea, which was a side sea for them, transform to lake within the territory of their empire and they succeeded to a large extent in this work.