Iran (lang-fa????? IPA-fa?i???nIran_alborz.ogg), officially the Islamic Republic of Iran is a country in Central Eurasia and/or Western Asia. The name Iran (Iran (word)) has been in use natively since the Sassanian era (Sassanid Empire) and came into use internationally in 1935, before which the country was widely known as Persia. Both Persia and Iran are used interchangeably in cultural contexts; however, Iran is the name used officially in political contexts. The name Iran is a cognate of Aryan, and means "Land of the Aryans".

The 18th largest country in the world in terms of area at 1,648,195 km�, Iran has a population of over 70 million. It is a country of particular geostrategic (geostrategy) significance owing to its location in the Middle East and central Eurasia. Iran is bordered on the north by Armenia, Azerbaijan and Turkmenistan. As Iran is a littoral (littoral zone) state of the Caspian Sea, which is an inland sea and condominium (Condominium (international law)), Kazakhstan and Russia are also Irans direct neighbors to the north. Iran is bordered on the east by Afghanistan and Pakistan, on the south by the Persian Gulf and the Gulf of Oman, on the west by Iraq and on the northwest by Turkey. Tehran is the capital, the countrys largest city and the political, cultural, commercial and industrial center of the nation. Iran is a regional power, and holds an important position in international energy security (Energy_superpower#Iran) and world economy (List of countries by GDP (PPP)) as a result of its large reserves of petroleum and natural gas.

Iran is home to one of the worlds oldest continuous major civilizations. The first Iranian dynasty formed during the Elamite kingdom in 2800 BCE. The Iranian Medes unified Iran into an empire in 625 BCE.Encyclop�dia Britannica Encyclopedia Article: Media ancient region, Iran They were succeeded by the Iranian Achaemenid Empire, the Hellenic Seleucid Empire and two subsequent Iranian empires, the Parthians (Parthian empire) and the Sassanids (Sassanid Empire), before the Muslim conquest in 651 CE. Iranian post-Islamic dynasties and empires expanded the Persian language and culture (Persian culture) throughout the Iranian plateau. Early Iranian dynasties which re-asserted Iranian independence included the Tahirids, Saffarids, Samanids and Buyids.

The blossoming of Persian literature, philosophy (Persian philosophy), medicine (Science and technology in Iran), astronomy (Science and technology in Iran), mathematics (Science and technology in Iran) and art (Persian art) became major elements of Muslim civilization and started with the Saffarids and Samanids. Iran was once again reunified as an independent state in 1501 by the Safavid dynasty?who promoted Twelver Shia Islam as the official religion of their empire, marking one of the most important turning points in the history of Islam. "Persias Constitutional Revolution" (Iranian Constitutional Revolution) established the nations first parliament (Majles) in 1906, within a constitutional monarchy. Iran officially became an Islamic republic on 1 April 1979, following the Iranian Revolution.

Iran is a founding member of the UN (United Nations), NAM (Non-Aligned Movement), OIC (Organisation of the Islamic Conference) and OPEC. The political system of Iran (Politics of Iran), based on the 1979 constitution (Constitution of Islamic Republic of Iran), comprises several intricately connected governing bodies. The highest state authority is the Supreme Leader (Supreme Leader of Iran). Shia Islam is the official religion and Persian is the official language.