Iran

The earliest known presence of hominins in Iran dates to around 800,000 years ago, in the Middle Paleolithic. Many Middle Paleolithic sites have been discovered, mainly in the Zagros Mountains in western Iran and some sites associated with Neanderthals. The Zarzian culture is documented in Iran during the Epipaleolithic (25,000–11,500 years ago). Agriculture first appeared in Iran some 12,000 years ago alongside better-documented settlements in the Fertile Crescent. The Chogha Golan site featured early domestication of emmer wheat. The contemporary site of Ganj Dareh also features the earliest known domestication of goats around 10,000 years ago.

The ancient city of Susa, which would become the capital of Elam and later a capital city of the Achaemenid empire, was first settled in 4400–4200 BC, adjacent to the modern site of Shush, Iran. The Kura–Araxes culture (c. 3400 – c. 2000 BC) existed in northwestern Iran and the Caucasus.

Iran is home to one of the world's oldest continuous major civilizations, with historical and urban settlements dating back to 4000 BC, including the Jiroft culture in southeastern Iran. Inscriptions in the Proto-Elamite script, which predates cuneiform, have been found from the early third millennium BC. The western part of the Iranian plateau participated in the traditional ancient Near East with Elam (3200–539 BC), and later with other peoples such as the Kassites, Mannaeans, and Gutians. The earliest Iranian peoples began to arrive from Central Asia in the 2nd millennium BC.

The Median dynasty ruled the earliest Iranian state. In 612 BC, Cyaxares and the Babylonian king Nabopolassar invaded Assyria and destroyed Nineveh, the Assyrian capital, which led to the fall of the Neo-Assyrian Empire. The Medes later conquered and dissolved Urartu as well.

The Achaemenids united all Persian tribes under Cambyses I. Under his son, Cyrus the Great, the Achaemenids defeated the Medes and established the Achaemenid Empire, the largest-ever Iranian state. Cyrus conquered the Lydian and Neo-Babylonian empires, creating an empire far larger than Assyria. His son, Cambyses II (r. 530–522 BC), conquered the last major power of the region, ancient Egypt, causing the collapse of its twenty-sixth dynasty.

After the death of Cambyses II, Darius the Great (r. 522–486 BC) ascended the throne by overthrowing the Achaemenid monarch Bardiya. …

Iran has an area of 1,648,195 km (636,372 mi), making it is the sixth-largest country entirely in Asia and the second-largest in West Asia. It lies between latitudes 24° and 40° N and longitudes 44° and 64° E. It is bordered to the northwest by Armenia, the Azeri exclave of Nakhchivan, and the Republic of Azerbaijan; 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 the west by Iraq and Turkey.

Iran is in a seismically active area. On average, an earthquake of magnitude 7.0 or higher occurs once every ten years. Most earthquakes are shallow-focus and can be very devastating, such as the 2003 Bam earthquake. Iran consists mostly of the Iranian Plateau, with its southwestern region on the Arabian plate.

Iran is one of the world's most mountainous countries; its landscape is dominated by rugged mountain ranges that separate basins or plateaus. The populous western Iran is the most mountainous, with ranges such as the Caucasus, Zagros, and Alborz. Mount Damavand is the highest point, at 5,610 m (18,406 ft), which is the highest volcano in Asia. Iran's mountains have impacted its politics and economics for centuries.

Northern Iran is covered by the lush lowland Caspian Hyrcanian forests, near the southern shores of the Caspian Sea. The east consists mostly of desert basins, such as the Kavir Desert, which is the country's largest desert, and the Lut Desert, as well as salt lakes. The Lut Desert features the highest recorded land skin temperature in the world with 70.7 °C recorded in 2005. Large plains are found along the coast of the Caspian and at the north end of the Persian Gulf, where Iran borders the mouth of the Arvand river. Smaller, discontinuous plains are found along the remaining coast of the Persian Gulf, Strait of Hormuz, and Gulf of Oman.

Iran's climate is diverse, ranging from arid and semi-arid to subtropical along the Caspian coast and northern forests. On the north edge of Iran, temperatures rarely fall below freezing and the area remains humid. Summer temperatures rarely exceed 29 °C (84.2 °F). Annual precipitation is 680 mm (26.8 in) in the eastern plains and more than 1,700 mm (66.9 in) in the west. …

The Supreme Leader, the Rahbar, the Leader of the Revolution or Supreme Leadership Authority, is the head of state and is responsible for supervision of policy. The president has limited power compared to the Rahbar. Key ministers are selected with the Rahbar's agreement, who has the ultimate say on foreign policy. The Rahbar is directly involved in ministerial appointments for defense, intelligence and foreign affairs, and other top ministries after submission of candidates from the president.

The Rahbar directly controls regional policy, with the Ministry of Foreign Affairs tasks limited to protocol and ceremonial occasions. Ambassadors to Arab countries, for example, are chosen by the Quds Force, which reports to the Rahbar. The Rahbar can order laws to be amended. The Setad, a state-owned enterprise under the Rahbar, was valued at $95 billion in 2013, accounts of which are secret even to the parliament.

The Rahbar is the commander-in-chief of the Armed Forces, controls military intelligence and security operations, and has the sole power to declare war or peace. The Rahbar also appoints the heads of the judiciary, state radio and television networks, commanders of the police and military, and members of the Guardian Council.

The Assembly of Experts is responsible for electing the Rahbar and has the power to dismiss him on the basis of qualifications and popular esteem. To date, the Assembly of Experts has not challenged any of the Rahbar's decisions nor attempted to dismiss him. The previous head of the judicial system, Sadiq Larijani, appointed by the Rahbar, said that it is illegal for the Assembly of Experts to supervise the Rahbar. Many believe the Assembly of Experts has become a ceremonial body without any real power. In February 2025, The New York Times reported that according to Karim Sadjadpour, an expert on Iran at the Carnegie Endowment for International Peace, there exist in the Islamic Republic of Iran two parallel systems. One system is ruled by the military and intelligence forces, who report to the Rahbar, and "who oversee the nuclear programme and regional proxies and are tasked with repression, hostage taking and assassinations". …

As of 2024, Iran has the world's 19th largest economy by PPP-adjusted GDP. It is a mixture of central planning, state ownership of oil and other large enterprises, village agriculture, and small-scale private trading and service ventures. Services contribute the largest percentage of GDP, followed by industry (mining and manufacturing) and agriculture. The economy is characterized by its hydrocarbon sector, manufacturing and financial services. With 10% of the world's oil reserves and 15% of gas reserves, Iran is an energy superpower. Over 40 industries are directly involved in the Tehran Stock Exchange.

Tehran is the economic powerhouse of Iran. About 30% of Iran's public-sector workforce and 45% of its large industrial firms are located there, and half those firms' employees work for government. The Central Bank of Iran is responsible for developing and maintaining the currency: the Iranian rial. The government does not recognise trade unions other than the Islamic labour councils, which are subject to the approval of employers and the security services. Iran was the first country to introduce a national basic income in Autumn 2010. Unemployment was 9% in 2022.

Budget deficits have been a chronic problem, mostly due to large state subsidies, that include foodstuffs and especially petrol, totaling $100 billion in 2022 for energy alone. In 2010, the economic reform plan was to cut subsidies gradually and replace them with targeted social assistance. The objective is to move towards free market prices and increase productivity and social justice. The administration continues reform, and indicates it will diversify the oil-reliant economy. Iran has developed a biotechnology, nanotechnology, and pharmaceutical industry. The government is privatising industries.

Iran has leading manufacturing industries in automobile manufacture, transportation, construction materials, home appliances, food and agricultural goods, armaments, pharmaceuticals, information technology, and petrochemicals in the Middle East. It is among the world's top five producers of apricots, cherries, cucumbers and gherkins, dates, figs, pistachios, quinces, walnuts, Kiwifruit and watermelons. International sanctions against Iran have damaged the economy. …

Iran's population grew rapidly from about 19 million in 1956 to about 85 million by February 2023. Iran's fertility rate has dropped dramatically, from 6.5 children born per woman to about 1.7 two decades later, leading to a population growth rate of about 1.39% in 2018. Due to its young population, studies project that the growth will continue to slow until it stabilises at around 105 million by 2050.

Iran hosts one of the largest refugee populations, with almost one million, mostly from Afghanistan and Iraq. As of 2025, Iran was home to an estimated four million Afghan migrants and refugees. According to the Iranian Constitution, the government is required to provide every citizen with access to social security, covering retirement, unemployment, old age, disability, accidents, calamities, health and medical treatment and care services. This is covered by tax revenues and income derived from public contributions.

Iran has one of the highest urban growth rates in the world. From 1950 to 2002, the urban proportion of the population increased from 27% to 60%. Iran's population is concentrated in its western half, especially in the north, north-west and west. Tehran, with a population of around 9.4 million, is Iran's capital and largest city. Iran's second most populous city, Mashhad, has a population of around 3.4 million, and is capital of the province of Razavi Khorasan. Isfahan has a population of around 2.2 million and is Iran's third most populous city. It is the capital of Isfahan province and was the third capital of the Safavid Empire.

Ethnic group composition remains a point of debate, mainly regarding the largest and second-largest ethnic groups, the Persians and Azerbaijanis, due to the lack of Iranian state censuses based on ethnicity.

According to a 2003 estimate, Persians make up 51% of the population, while Azerbaijanis make up 24%, Gilaks and Mazanderanis 8%, Kurds 7%, Arabs 3%, Lurs 2%, Balochis 2%, Turkmens 2%, and other groups (including Armenians, Jews, Assyrians, Qashqai, Shahsevan) make up the remaining 1%. The World Factbook at 2011 gives the same figures. …