Overview
Civilization on the Iranian plateau reaches back to Elam in the 3rd millennium BC, making Iran home to one of the world’s oldest continuous civilizations. For centuries Persia was Rome’s great eastern rival, and Zoroastrianism was the dominant religion before Islam. The Safavids (1501–1736) made Twelver Shia Islam the state religion, shaping Iran’s religious identity to this day.
The major eras
The Achaemenid Empire, founded by Cyrus the Great in 550 BC, is commonly described as the largest empire the world had yet seen, stretching from the Indus to Egypt and the Aegean; after Alexander’s conquest came the Seleucid, Parthian and Sasanian empires. The Arab conquest (633–654) brought Islam, yet Persian language and culture — Ferdowsi’s Shahnameh, Persian poetry, science and art — flourished within the Islamic world under successive dynasties such as the Seljuks, Ilkhanids and Timurids. After the Safavids fixed the country’s Shia identity, the Qajars faced growing European pressure, and the Constitutional Revolution (1905–1911) created one of Asia’s first parliaments. The Pahlavi era (1925–1979) pursued rapid, authoritarian modernization, and the 1979 Islamic Revolution created the Islamic Republic, whose history since — war with Iraq, the nuclear standoff, waves of protest — remains contested and consequential.