Iran

Iran, officially the Islamic Republic of Iran (IRI) and also known as Persia, is a country in West Asia. It borders Iraq to the west, Turkey, Azerbaijan, and Armenia to the northwest, the Caspian Sea to the north, Turkmenistan to the northeast, Afghanistan to the east, Pakistan to the southeast, and the Gulf of Oman and the Persian Gulf to the south. With a multi-ethnic population of over 92 million in an area of 1,648,195 km² (636,372 sq mi), Iran ranks 17th globally in both geographic size and population. It is the sixth-largest country entirely in Asia and one of the world's most mountainous countries. Iran is officially an Islamic republic, divided into five regions with 31 provinces. Tehran is the nation's capital, largest city and financial centre.

A cradle of civilisation, Iran has been inhabited since the Lower Palaeolithic. The large part of Iran was first unified as a political entity by the Medes under Cyaxares in the seventh century BCE and reached its territorial height in the sixth century BCE, when Cyrus the Great founded the Achaemenid Empire. Alexander the Great conquered the empire in the fourth century BCE. An Iranian rebellion in the third century BCE established the Parthian Empire, which later liberated the country. In the third century CE, the Parthians were succeeded by the Sasanian Empire, whose era was considered a golden age in the history of Iranian civilisation. Ancient Iran saw some of the earliest developments of writing, agriculture, urbanisation, religion and administration. Once a centre for Zoroastrianism, the Muslims conquered the region in the seventh century CE, leading to the Islamization of Iran. The literature, philosophy, mathematics, medicine, astronomy and art which blossomed during the Sasanian era were renewed during the Islamic Golden Age and Iranian Intermezzo, when a series of Iranian Muslim dynasties ended Arab rule, revived the Persian language and ruled the country. This era was followed by the Seljuk and Khwarazmian rule, Mongol conquests and Timurid Renaissance from 11th to 14th centuries.

In the 16th century, the native Safavid dynasty re-established a unified Iranian state with Twelver Shia Islam as the official religion. During the Afsharid Empire in the 18th century, Iran was a leading world power, but this was no longer the case after the Qajars took power in the 1790s. The early 20th century saw the Persian Constitutional Revolution and the establishment of the Pahlavi dynasty by Reza Shah, who ousted the last Qajar Shah in 1925. Attempts by Mohammad Mosaddegh to nationalise the oil industry led to a Anglo-American coup in 1953. After the Iranian Revolution, the monarchy was overthrown in 1979 and the Islamic Republic of Iran was established by Ruhollah Khomeini, who became the country's first supreme leader. In 1980, Iraq invaded Iran, sparking the eight-year-long Iran–Iraq War, which ended in a stalemate.

Iran is officially governed as a unitary Islamic republic with a presidential system, with ultimate authority vested in a supreme leader. The government is authoritarian and has attracted widespread criticism for its violations of human rights and civil liberties. Iran is a major regional power, due to its large reserves of fossil fuels, including the world's second largest natural gas supply, third largest proven oil reserves, its geopolitically significant location, military capabilities, cultural hegemony, regional influence, and role as the world's focal point of Shia Islam. The Iranian economy is the world's 23rd-largest by PPP. Iran is a founding member of the United Nations, OIC, OPEC, and ECO as well as a current member of the NAM, SCO, and BRICS. Iran is home to 28 UNESCO World Heritage Sites, the 10th highest in the world and ranks 5th in intangible cultural heritage, or human treasures.