During its early history, the land of Iran was known as the Persian Empire. The first great Empire in Iran was the Achaemenid dynasty, which ruled from 550 to 330 BC. It was founded by the Great Cyrus. This period was followed by the conquest of Alexander, and the Hellenistic period. After Alexander, the Parthian dynasty ruled for nearly 500 years and followed by the Sassanian dynasty until 661 CE. In the 7th century, the Arabs came to power in Iran and introduced the people to Islam. Other invasions came, first from the Turks and later from the Mongols. From the early 1500s, local dynasties regained power, including Afsharid, Zand, Qajar, and Pahlavi.
In 1979, the Pahlavi dynasty was overset by the Iran Islamic revolution. The Shah (king) left the country and the Islamic religious leader, Ayatollah Khomeini, became the leader of the theocratic republic.
2700 - The Elamite civilization emerges in western Iran.
1500 - The Anshanite dynasties begin to rule over Elam.
1100 - The Elamite empire reaches the peak of its power.
678 - The Medes of northern Iran rise to power with the fall of the Assyrian Empire and form the Median Empire.
550 - Cyrus the Great and the Achaemenid Empire conquers much of the region forming the Persian Empire.
330 - Alexander the Great leads the Greeks to victory over the Persians.
312 - The Seleucid Empire is formed by one of Alexander's generals. It will rule much of the region until overthrown by the Roman Empire.
140 - The Parthian Empire takes control and rules Iran and the surrounding region.
224 - The Sassanid Empire is founded by Ardashir I. It will rule for over 400 years and is the last of the Iranian Empires.
421 - Bahram V becomes king. He will later become the subject of many tales and legends.
661 - The Arabs invade Iran and conquer the Sassanid Empire. They bring the Islamic religion and Islam rule to the region.
819 - The Samanid Empire rules the region. Islam is still the state religion, but the Persian culture is revived.
977 - The Ghaznavid dynasty takes over much of the region.
1037 - The rise of the Seljuq Empire was founded by Tughril Beg.
1220 - The Mongols invade Iran after Mongol emissaries are killed. They destroy many cities, killed much of the population, and caused devastation across Iran.
1350 - The Black Death hits Iran killing around 30% of the population.
1381 - Timur invades and conquers Iran.
1502 - The Safavid Empire is established by Shah Ismail.
1587 - Shah Abbas I the Great becomes king of the Safavid Empire. The empire reaches its peak under his rule becoming a major world power.
1639 - The Safavid Empire agrees to a peace agreement with the Ottoman Empire called the Treaty of Zuhab.
In the 1650s - Iran begins to lose territories to European countries such as Great Britain, Russia, and France.
1736 - A weakened Safavid Empire is overthrown by Nadir Shah.
1796 - The Qajar dynasty is established after a civil war.
1813 - The Russians defeat the Persians in the Russo-Persian War.
1870 - A great famine kills over a million people in Persia.
1905 - The Persian Constitutional Revolution occurs. A parliamentary government is created. The parliament is called the Majlis.
1908 - Oil is discovered.
1914 - World War I begins. Iran remains neutral but is occupied by various forces including Great Britain, Russia, and the Ottoman Empire.
1919 - After World War I, Great Britain tries unsuccessfully to establish a protectorate in Iran.
1921 - Reza Khan captures Tehran and seizes power. He will be made prime minister in 1923 and Shah of Iran in 1925. He brings modernization to Iran but is resented by devout Muslims.
1935 - The official name for the country is changed to Iran from Persia.
1939 - World War II begins. Iran remains neutral but is friendly towards the Axis powers.
1941 - the Soviet Union and British forces invade Iran in order to
1941 - A new Shah, Mohammad Reza Pahlavi, is put into power.
1951 - The Iranian parliament nationalizes the oil industry.
1979 - The Shah is forced into exile and Islamic leader Ayatollah Khomeini takes over. The Islamic Republic of Iran is declared.
1980 - The Shah dies of cancer.
1980 - The Iran-Iraq war begins.
1988 - A ceasefire is agreed to with Iraq.
2005 - Mahmoud Ahmadinejad becomes president.
2014 - Hassan Rohani becomes president.