Iran(Persian:ایران Iran(About this soundlisten)), also called Persia, and officially the Islamic Republic of Iran (Persian:جمهوری اسلامی ایران jomhuri-ye Eslami-ye iran (About this soundisten),is a country in western Asia .it is bordered to the northwest by Armenia and Azerbaijan,[a] to the north by the caspian sea, to the northeast by turkmenistan, to the east by Afghanistan and pakistan, to the south by the Persian gulf and the gulf of oman, and to west by turkey and Iraq. Its central location in Eurasia and proximity to the Straite of Hormuz give it significant geostrategic importance. Tehran is the capital and largest city, as well as the leading economic and cultural hub; it is also the most populous city in western asia, with more than 8.8 million residents, and up to 15 milllion including the metropolitan area. With million inhabitants, iran is the world’s 17th most populous country. Spanning 1,648,195 km2 (636,372 sq mi), it is the second largest country in the Middle East and the 17th largest in the world.
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 Iranians Medes in the seventh century BC, and reached its territorial height in the sixth century BC, when Cyrus the Great founded the Achaemenid Empire, which stretched from Eastern Europe to the Indus Valley, making it 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 parthain Empire in the third century BC, which was succeeded in the third century AD by the Sasanian Empire, a major world power for the next four centuries.