Linguistically, Iran means the land of Aryans, the eastern branch of Indo-Europeans. A group of Aryans (or Indo-Iranians) who migrated to the Iranian plateau around 2000 BCE from Central Asia, are thought to be the direct ancestors of modern Iranians, This has encouraged many historians to start the history of Iran from the Aryan migrations or the establishment of the first Aryan political power, the Achaemenid Empire. At the same time, it is true that long before the influx of Aryans into Iran, different peoples with established civilizations and kingdoms inhabited the country. These dynasties that deteriorated before the arrival of the Aryans or were defeated by them had an extensive system of international trade and relations with other civilizations of their time, as far west as Egypt and maybe Southern Europe and to China in the east. In 6th century BC Cyrus the Great founded the Persian Empire, which was destroyed in 330 BC by Alexander the Great. In the following centuries, Persia was ruled by Greeks, Parthians, and Sassanids until the Arab invasion in the middle 7th century when the ancient Persian religion of Zoroastrianism gave way to Islam. Four centuries later, in the 11th century, The Seljuk Turks arrived, followed by the Mongols under Genghis Khan and his grandson Hulagu Khan in the 13th century and Tamerlane (Timur) in the 14th century. Another Turkish dynasty from Azarbijan region, called Safavids, took control in the 16th century. Safavids belonged to a Sufi religious order and made Shiite Islam the official religion of Iran, undertaking a major conversion campaign of Iranian Muslims. The Safavid dynasty reached its height during the reign of Shah Abbas 1st (1587-I629). It was during his reign that Persia once again came to be known in Europe as a superpower, because it was the greatest opponent of the Ottomans, and their wars saved Europe, the Ottomans being too occupied on the east fighting Iran to make headway in the west.
In 18th-19th century under Qajar dynasty, centuries Iran fall under the increasing pressure of European nations, particularly the Russian Empire and the Great Britain. The discovery of oil in early 1900s intensified the rivalry of the Great Britain and Russia for power over the nation. After the first world war Iran was admitted to the United Nations as an original member.
In 1921 Reza Khan, an army officer, established a military dictatorship. He was subsequently elected hereditary Shah, thus ending the Qajar dynasty and founding the new Pahlavi dynasty.

The Achaemenid Persian empire

The Achaemenid Persian empire was the largest that the ancient world had seen, extending from Anatolia (current Turkey) and Egypt across western Asia to northern India and Central Asia. The foundation of Achaemenids began in 550 B.C., when King Astyages of Media, who dominated much of Iran and eastern Anatolia, was defeated by his southern neighbor (or his grand son)  Cyrus the Great, a persia ruler (r. 559–530 B.C.). This upset the balance of power in the Near East. The Lydians of western Anatolia and The Babylonian Empire who controlled Mesopotamia and the eastern Mediterranean were later defeated by Cyrus the great. In 539 B.C. Cyrus entered Babylon and presented himself as a traditional Mesopotamian monarch, restoring temples and releasing political prisoners. The one western power that remained unconquered in Cyrus’ lightning campaigns was Egypt. This task was left to his eldest son and crown prince Cambyses to rout the Egyptian forces in the eastern Nile Delta in 525 B.C. After a ten-day siege, Egypt’s ancient capital Memphis fell to the Persians.

Persepolis, Iran

A crisis at court forced Cambyses to return to Persia but he died mysteriously en route and his commander in chief Darius was crowned as king (r. 522–486 B.C.), claiming in his inscriptions that “Achaemenes” was his ancestor. Under Darius the great the empire was stabilized, with roads for communication and a system of governors (satraps) established. He added northwestern India to the Achaemenid realm and initiated two major building projects: the construction of royal buildings at Susa and the creation of the new dynastic center of Persepolis, the buildings of which were decorated by Darius and his successors with stone reliefs and carvings. These show tributaries from different parts of the empire processing toward the enthroned king or conveying the king’s throne. The impression is of a harmonious empire supported by its numerous peoples. Darius also consolidated Persia’s western conquests in the Aegean. However, in 498 B.C., the eastern Greek Ionian cities, supported in part by Athens, revolted. It took the Persians four years to crush the rebellion, although an attack against mainland Greece was repulsed at Marathon in 490 B.C.

Darius’ son Xerxes (r. 486–465 B.C.) attempted to force the mainland Greeks to acknowledge Persian power, but Sparta and Athens refused to give way. Xerxes led his sea and land forces against Greece in 480 B.C., defeating the Spartans at the battle of Thermopylae and sacking Athens. However, the Greeks won a victory against the Persian navy in the straits of Salamis in 479 B.C. It is possible that at this point a serious revolt broke out in the strategically crucial province of Babylonia. Xerxes quickly left Greece and successfully crushed the Babylonian rebellion. However, the Persian army he left behind was defeated by the Greeks at the Battle of Plataea in 479 B.C.

Much of our evidence for Persian history is dependent on contemporary Greek sources and later classical writers, whose main focus is the relations between Persia and the Greek states, as well as tales of Persian court intrigues, moral decadence, and unrestrained luxury. From these we learn that Xerxes was assassinated and was succeeded by one of his sons, who took the name Artaxerxes I (r. 465–424 B.C). During his reign, revolts in Egypt were crushed and garrisons established in the Levant. The empire remained largely intact under Darius II (r. 423–405 B.C), but Egypt claimed independence during the reign of Artaxerxes II (r. 405–359 B.C). Although Artaxerxes II had the longest reign of all the Persian kings, we know very little about him. Writing in the early second century A.D., Plutarch describes him as a sympathetic ruler and courageous warrior. With his successor, Artaxerxes III (r. 358–338 B.C), Egypt was reconquered, but the king was assassinated and his son was crowned as Artaxerxes IV (r. 338–336 B.C.). He, too, was murdered and replaced by Darius III (r. 336–330 B.C.), a second cousin, who faced the armies of Alexander the Great. Ultimately Darius III was murdered by one of his own generals, and Alexander claimed the Persian Empire.

Sasanian empire

The name “Sasanians” is derived from a Persian priest named Sasan, the ancestor of the dynasty. Sasan’s grandson Ardashir I defeated the last Parthian king Artabanus IV in 226. He took Ctesiphon, the capital of the Parthian empire and ended Parthian dynasty, Ardashir accepted the title of “king of kings”, which had until then been used by the Parthian kings and – centuries before – the Achaemenid rulers of Persia.

In the Sasanian rock reliefs and inscriptions, we often see “investiture scenes”, in which the god Ahuramazda, seated on a horse, hands over power to a king. These “Mazda-worshiping kings”, or believers in the supreme god Ahuramazda conferred many privileges to the Magians, the religious specialists of Zoroastrianism, who gained great political power by playing a role in the inauguration ceremony in Ctesiphon, served as judges and tax collectors.

As a consequence of this religious ideology, there was little room for alternative ideas. Christians were persecuted, and the prophet Mani (216-276), who had tried to combine Christianity, Buddhism, and Zoroastrianism, was crucified.

The conflict with Rome, which had started in 231 with some fighting on the Euphrates, escalated under Ardashir’s son and successor Shapur I (r.241-272). According to Roman sources, he made territorial claims: he wanted to restore the Achaemenid Empire and demanded all Roman territories in Asia, a claim that was implied in his title “king of Iran and non-Iran”.

Nevertheless, to reach Nisibis, Shapur raided large parts of the Roman East. When he invaded Syria and looted Antioch, a Roman counterattack was inevitable. The emperor Gordian III invaded Mesopotamia and was at first successful, but was killed in action during a battle near Ctesiphon (244). His successor, Philip the Arab, was forced to conclude a shameful peace treaty, and with some justification, Shapur claimed to have put Philip on the Roman throne. Roman POWs were forced to build the city of Bishapur, where a rock relief commemorated his triumph.

The next phase of the war was even more disastrous to the Romans. Their emperor Valerian was not just defeated, he was even captured (260). The humiliation, shown on rock reliefs at Bishapur and Naqsh-e Rustam, could not be more complete. However, under the emperors Odaenathus (r.261-267), Carus (r.282-283), and Diocletian (r.284-305), the Romans restored their fortunes and in 298, a peace treaty was concluded in which the Persians had to give up territories in northern Mesopotamia.

Shapur also attacked the Kushans, who ruled the region known as Gandara, the valley of the river Kabul. The Persians took their capital Peshawar and deposed the ruling dynasty. A precious religious object, Buddha’s begging bowl, was taken to Persia.

King Shapur II (r.309-379) attacked the Roman possessions in Mesopotamia, and defeated and killed the Roman emperor Julianus Apostata who had come to punish the attacker .The Romans were forced to give up the conquests of 298.

Like his namesake, Shapur II attacked the Kushan kingdom, which he overthrew. The sphere of influence of the Sasanian Empire now reached to the borders of China. Shapur also invaded Arabia. Other enemies were the White Huns, who invaded the Sasanian empire during the fifth century.

What is true, however, is that several religious groups coexisted more or less peacefully. The main exception is a religious jacquerie in Iran that is called Mazdakism. Its adherents had several ideas that remind us of pre-leninist communism. King Khusrau I “the deathless soul” suppressed it in 530s, and its adherents may have fled to Arabia.

The final struggle of the Roman Empire – now called Byzantine Empire – and Persia started under Khusrau II “the victorious” (r.590-628). Again, the Sasanians were the aggressor. The Byzantines were weakened, because Italy had been invaded by the Langobards, the Slavs were taking hold of the Balkans, and Andalusia was lost to the Visigoths. It was the perfect moment to attack the Byzantine empire, and Khusrau acted accordingly. His armies ravaged the cities of Syria and sacked Jerusalem in 614. (The Jews welcomed the Persians, because the Christians had often persecuted them.) One of the objects the Persians took away was the relic of the True Cross.

Khusrau’s armies went on to invade Egypt – Alexandria was captured in 619 – and in 626, their advance-guards paused only a mile from Constantinople. The Persians even raided Cyprus and occupied Rhodes. It seemed as if the Achaemenid Empire was restored, and Khusrau ordered the making of brilliant rock reliefs at Taq-e Bostan.

However, the Byzantine emperor Heraclius was to prove a match for Khusrau. In 627, he invaded Assyria and Mesopotamia. His campaign was extremely successful: he did not even return to his own empire during the winter, but stayed far behind the enemy lines. The Persian army mutinied and Khusrau was murdered (628). His successor Ardašir IV made peace and the relic of the True Cross was restored to Jerusalem.

Heraclius’ victory meant the end of Persia. There were four Sasanian kings in four years, and because there was no real authority, the Arabs – Muslims – were able to defeat the Persians, who were still Zoroastrians. The last Persian king was Yazdgard III, whose reign began in 632. In 636, the Arabs took Ctesiphon, in 641, they invaded Iran (battle of Nehavand), and ten years later, the last Sasanian king died as a fugitive.

Under Khusrau II, the Zoroastrian high priest established Avesta, the holy book of Zoroastrianism, containing hymns of great antiquity, cosmogony and law, a biography of the prophet Zarathustra.

Timeline of Iranian history

B.C.E.

100,000 Evidence ofhuman habitation in Zagros.
8000E Development of settled village in Zagros.
5500 The oldest settlements in Sialk, Central lran.
4200 Susa is founded in southwestern Persia.
3200-2700 Proto-Elamite period.
2700 Elamite Kingdom with Susa as capital.
2700-1600 Old Elamite period.
1500-1100 Middle Elamite period.
1100-539 Neo-Elamite periods.
1000 birth of Zoroaster, Iranian prophet
708 Deioces founds Median Kingdom in Ecbatana.
633 Scythian Invasion of Media.
624 Medians defeat and oust the Scythians.
558 Cyrus the Great moves the capital to Susa.
546 Cyrus invades Lydia
539 Cyrus captures Babylon.
539 Cyrus allows exiled Jews return to Jerusalem
529 Death of Cyrus the great.
525 Cambyses conquers the conquet of Egypt.
521 Death of Cambyses, son of Cyrus.
521 Darius ascends the throne.
514 Darius invades Scythia, Caucasus.
494 Invasion of Greece by Darius.
490 Defeat of Persians at the Battle of Marathon.
486 death of Darius, Accesson of Xerxes I.
484 Xerxes suppresses the revolt in Babylon.
479 Battle of Plataea, Greek defeat of the Persians.
405 The Persian Empire loses Egypt.
404 Accession of Artaxerxes II to the throne.
359 Accession of Artaxerxes III.
342 Egypt is re-conquered.
336 Darius III, ascends to the throne.
334 Alexander the Great defeats the Persian army.
330 Assassination of Darius III.
327-326 Alexander invades India.
323 Alexander returns to Babylon, and dies at 33.
320Seleucus I (Nicator) founds the Seleucid Empire.
247 Arsaces I (Arshak) founds the Parthian dynasty.

C.E.

214-17Birth of the prophet Mani
224  Establishment of the Sasanians by Ardashir I
241 Accession of Shapur I.
259 Emperor Valerianus is defeated by Shapur I.
274 or 277 Execution of Mani.
363 Julian killed in a war against Persia.
376 Peace established between Rome and Persia.
531 Massacre and suppression of the Mazdakites.
531 Administrative, military, and social reforms.
533 Peace with Byzantium.
570 Conquest of Yemen.
570 Birth of the Prophet Moḥammad.
611-16 Ḵosrow II’s conquest of Syria and Egypt.
622 Moḥammad’s move from Mecca to Medina,
632 Death of Prophet Moḥammad.
632-34 Abu Bakr’s caliphate.
633 Yazdegerd III succeeds to the Persian throne.
636 Persians are defeated by Arabs at Qadesiya.
637 Muslims capture Ctesiphon, the Sasanian capital
637 Arab Muslim conquest of Mesopotamia.
642 Defeat of Persians by Muslims at Nehavand.
651 Murder of Yazdegerd III; end of the Sasanians
656 Murder of Othman; Ali is chosen as caliph.
680 Revolt of Ḥusain b. Ali, the third Shiʿite Imam.
680 Death of Hussein at the battle of Karbala.
749 Abu Moslem’s army attacks the Omayyads.
750 Establishment of the Abbasid dynasty.
755 Murder of Abu Moslem by caliph Manṣur.
813 The pro-Persian Maʾmun is elected caliph.
820 Ṭaher establishes the Taherid dynasty.
833 Death of Maʾmun.
878 Mahdi, the twelfth Shiʿism disappears.
903 Rise of the Samanid dynasty.
925 Death of Abu Bakr Moḥammad Rāzi
935 foundation of  the Buyid dynasty
940 Death of Rudaki “father of Persian poetry,”
977 Foundation of Ghaznavid dynasty.
999 Ferdowsi completes the first draft of Šāh-nāma.
1019 or 1025 Death of Persian poet, Ferdowsi
1037 Rise of the Saljuqids.
1037 Death of Avicenna, Persian physician.
1078-87 foundation of Ismailis by Ḥasan Ṣabbaḥ.
1132 Death of Omar Khayyam.
1157 End of Saljuqids, rise of the Ḵharazmshahins.
1209 Death of Neẓāmi Ganjavi, prominent poet.
1220 Genghis Khan overthrows the Ḵharazmshahis.
1221 Death of Farid-al-Din Aṭṭar, mystic poet.
1227 Genghis Khan dies.
1258 End of the Abbasid caliphate.
1271 Marco Polo journeys through Persia.
1273 Death of Jalal-al-Din Rumi, poet.
1313-93 Mozaffarid dynasty in Yazd and Fars.
1378 Establishment of the Aq Qoyunlu rulers.
1389 Establishment of the Qara Qoyunlu.
1390 Death ofḤafeẓ, the Persian lyric poet.
1393 Timur defeats the Mozaffarids.
1397 Timur invades India.
1405 Death of Timur.
1500-06 Overthrow of the Timurids.
1501 Esmaʿil I establishes the Safavid dynasty.
1502-24 Esmaʿil I establishes Shiʿite official religion.
1507 Portuguese fleet occupies Hormuz.
1508 Safavid forces capture Iraq.
1514 Chaldoan battle;Selim I defeats Esmaʿil.
1514-20 Ottoman economic boycott of Persia.
1548 Ṭahmasb transfers his capital to Qazvin.
1585 Ottomans invade Persia and occupy Tabriz.
1588 Accession of Abbas I (the Great).
1590 Shah Abbas makes peace with the Ottomans.
1598 Shah Abbas’ victory over the Uzbeks.
1600 Shah Abbas transfers his capital to Isfahan.
1601-03 Shah Abbas occupies Bahrain.
1603 War with Ottomans; Abbas retakes Tabriz.
1603-04 deportation of Armenians to New Julfa.
1622 Persians oust the Portuguese from Hormuz.
1629 Death of Shah Abbas I.
1630 The Ottomans capture Hamadan.
1638 The Ottomans capture Erevan and Tabriz.
1664 First Russian mission sent to Isfahan.
1664 A French trade mission is sent to Persia.
1697-1701 The Safavids control Basra.
1722 The Afghans under Maḥmud invade Isfahan.
1722-30 The Afghans occupy much of Persia.
1723 The Russians occupy Rasht and Baku.
1723 Ottomans occupy Georgia and Hamadan.
1724 Maḥmud captures Shiraz.
1725 The Ottomans occupy Ganja and Tabriz.
1729 Nader defeats Afghans.
1733 Nader ends the Ottoman occupation.
1734 Nader invades the Caucasus,Baku, Erevan.
1736 Nader is proclaimed Shah; end of Safavids.
1738 Nader Shah occupies Qandahar.
1739 Nader invades India.
1740 Nader Shah conquers Bukhara and Ḵiva.
1747 Assassination of Nader Shah.
1758 Karim Khan becomes ruler of Persia.
1779 Karim Khan dies at the age of 80.
1783 The Persians are driven from Bahrain.
1794 Aqa Moḥammad Khan establishes Qajar.
1796 Coronation of Aqa Moḥammad Khan.
1797 Assassination of Aqa Moḥammad Khan.
1810 First Persian students are sent to Europe.
1812 Treaty of friendship between Persia and Britain.
1813 First war with Russia; Abbas Mirza is defeated.
1813 Treaty of Golestan; Persia cedes Georgia.
1826 Second war with Russia; defeat of Persians.
1826 Turkmenchay treaty with Russia.
1836 Rebellion of Aqa Khan against government.
1844 Foundation of Babi movement.
1848 Accession of Nāṣer-al-Din Shah.
1850 Execution of the Bab by order of Amir Kabir.
1850 Amir Kabir is exiled to Kashan.
1851 Inauguration of the Dār-al-Fonun College.
1852 Execution of Amir Kabir iby Naṣer-al-Din Shah.
1852 Massacre of the Babis by Naṣer-al-Din Shah.
1857 Shah recognizes independence of Afghanistan.
1860 Freemasonry is introduced in Persia.
1891  tobacco boycott by  Mirzā Ḥasan Shirzi.
1892 Death of Baha Allah, founder of the Bahāis.
1896 Assassination of Nāṣer-al-Din Shah.
1904 Tea plant seed is imported from India.
1906 First formation of a national assembly.
1906 The first Majles opens on October 7.
1908 Excavation of oil at Masjed-e Solayman.
1908 movement of Sattar Khan and Baqer Khan.
1909 Execution of Shaikh Fażl-Allāh Nuri.
1909 Formation of the Anglo-Persian Oil Company..
1915 Movement of Mirza Kuchak Khan in Gilan.
1915 British forces enter Bushehr.
1916 Russian forces occupy Qom and Kashan.
1920 Mirza Kuchak Khan occupies Rasht.
1921 Reża Khan defeats Kuchak Khan.
1921 Founding of the Qom religious center.
1923 Reża Khan assumes the premiership.
1923 Aḥmad Shah leaves for Europe,
1925 Majles approves the deposing of Aḥmad Shah.
1925 Reża Khan is elected Shah.
1928 Formation of Bank-e Melli (National Bank).
1928 Bandar-e Anzali is renamed Bandar-e Pahlavi.
1930 Political relations established with Japan.
1934 Reza Shah visits Turkey and Kemal Ataturk.
1935 Inauguration of the University of Tehran.
1935 Adoption of Western-style uniform dress
1935 Uprising in the Gowharshad Mosque.
1936 Women are banned from wearing veil (chador).
1939 Prince Moḥammad Reza marries Fawzia.
1939 Iran declares its neutrality in the World War II.
1941 Reza Shah is overthrown
1943 Tehran Conference.
1944 Death of Reza Shah in Johannesburg.
1948 The Shah and Queen Fawzia divorce.
1950 Military agreement between Iran and US.
1951 Shah marries Sorayya Esfandiari.
1951 The Oil Nationalization Law is passed.
1951 Moṣaddeq is named prime minister.
1952 Moḥammad Moṣaddeq resigns.
1953 Dismission of Mosaddegh by Shah.
1957 Formation of SAVAK, Iranian secret police.
1959 The Shah marries Faraḥ Diba.
1960 Inauguration of the Central Bank of Iran.
1962 Inauguration of Iran Air, the national airline.
1962 Formation of the Iran National Car Company.
1964 Ayatollah Khomeini is exiled to Turkey.
1966 National Iranian television begins broadcasting.
1967 Death of Moḥammad Moṣaddeqm.
1971 Iran occupies Abu Musa Island.
1971 Celebrations of 2,500th anniversary of foundation of the Persian monarchy
1972 President Richard Nixon visits Iran.
1979 Islamic revolution