Nationalist Prime Minister Mohammed Mossadeq attempts to nationalize the British-owned oil industry. The shah opposes Mossadeq and removes him from power, but he regains power and the shah leaves Iran.
The Shah returns to Iran when General Fazlollah Zahedi--with backing from the Central Intelligence Agency -- overthrows Mossadeq in an August coup d'etat.
According to the Federation of American Scientists, U.S. and Israeli intelligence officers work with Iran to set up SAVAK, an Iranian intelligence organization later blamed for the torture and execution of thousands of political prisoners and violent suppression of dissent.
Shah giving land deeds during the "The White Revolution"
The shah implements "The White Revolution," an aggressive campaign of social and economic Westernization that is met with intense popular opposition. Popular nationalist Ayatollah Khomeini is arrested in one of many crackdowns on the shah's opponents. By the late 1960s the shah relies regularly on SAVAK to quell dissidence.
In one of a series of reforms that alienate his people, the Shah replaces the Islamic calendar with an "imperial" calendar, beginning with the founding of the Persian Empire. Many of the shah's growing number of critics see this as anti-Islamic.
Iranians resort to rioting, mass demonstrations and strikes to protest the shah's authoritarian rule. In response, he enforces martial law.