Iran, also known as Persia and officially the Islamic Republic of Iran (IRI), is a country in West Asia. It is bordered by Iraq to the west and Turkey to the northwest, Azerbaijan, Armenia, the Caspian Sea and Turkmenistan to the north, Afghanistan to the east, Pakistan to the southeast, the Gulf of Oman and the Persian Gulf to the south. It covers an area of 1.64 million square kilometers (0.63 million square miles), making it the world's 17th-largest country. Iran has around 90 million people, making it the world's 17th most populous country. Its capital and largest city is Tehran. 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 Medes in the seventh century BC and reached its territorial height in the sixth century BC, when Cyrus the Great founded the Achaemenid Empire. Alexander the Great conquered the empire in the fourth century BC, and it was subsequently 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. Arab Muslims conquered the empire in the seventh century AD, leading to its Islamization; Iran thereafter became a major center of Islamic culture and learning. Over the next two centuries, a series of native Iranian Muslim dynasties emerged before the Seljuk and the Mongols conquered the region. In the 16th century, the native Safavids re-established a unified Iranian state. Under the reign of Nader Shah in the 18th century, Iran presided over the most powerful military in the world, though by the 19th century, a series of conflicts with the Russian Empire led to significant territorial losses. The early 20th century saw the Persian Constitutional Revolution. Efforts to nationalise its fossil fuel supply led to an Anglo-American coup in 1953. After the Iranian Revolution, the current Islamic Republic was established in 1979 by Ruhollah Khomeini, who became the country's first supreme leader. The Iranian government is an Islamic republic with a presidential system, though ultimate authority is vested in a theocratic "Rahbar"; the position has been held by Ali Khamenei since Ayatollah Khomeini's death in 1989. The Iranian government is authoritarian, and has attracted widespread criticism for its significant constraints and violations of human rights and civil liberties. It is also a focal point for Shia Islam within the Middle East. Since the Iranian Revolution, the country is considered to be the most determined adversary of Israel and Saudi Arabia. On March 10, 2023, Iran and Saudi Arabia normalized relations after years of hostility. The Iranian government has been criticised for various policies such as its alleged sponsorship of terrorism, funding of proxy militias and its involvement in the majority of modern Middle Eastern conflicts. Iran is a regional and middle power and occupies a strategic location in the Asian continent. It is a founding member of the United Nations, the ECO, the OIC, the OPEC, the SCO, and is expected to join BRICS on 1 January 2024. It has large reserves of fossil fuels—including the second largest natural gas supply and the third-largest proven oil reserves. Historically a multi-ethnic country, Iran remains a pluralistic society comprising numerous ethnic, linguistic, and religious groups. The country's rich cultural legacy is reflected in part by its 27 UNESCO World Heritage Sites, which ranks 10th worldwide. Iran places 5th globally in terms of Intangible Cultural Heritage. Source: Wikipedia (en)