IRAN

Iran is home to one of the world's oldest civilizations, beginning with the formation of the Elamite kingdoms in the fourth millennium BC.

It was first unified by the Iranian Medes in the seventh century BC, and reached its territorial height in the sixth century BC under Cyrus the Great, whose Achaemenid Empire stretched from Eastern Europe to the Indus Valley, one of the largest empires in history.

The empire fell to Alexander the Great in the fourth century BC and was divided into several Hellenistic states. An Iranian rebellion established the Parthian Empire in the third century BC, which was succeeded in the third century AD by the Sasanian Empire, a leading world power for the next four centuries.