The Iranian Revolution was a popular uprising that transformed Iran from an absolute monarchy into an Islamic republic.

The country was ruled by Shah Mohammad Reza Pahlavi, a pro-Western monarch.

The Shah's policies of rapid modernization, secularization (the 'White Revolution'), and close ties to the United States alienated many conservative Iranians.

His regime was also known for its political repression, carried out by his secret police, the SAVAK.

The leader of the opposition was Ayatollah Ruhollah Khomeini, a charismatic Shia cleric who had been exiled by the Shah.

From exile, Khomeini's message calling for the overthrow of the Shah was spread throughout Iran on cassette tapes.

In 1978, mass protests, strikes, and demonstrations paralyzed the country.

The Shah fled Iran in January 1979, and Khomeini returned from exile to a massive welcome.

Following a referendum, the Islamic Republic of Iran was established, a theocracy based on Khomeini's principle of rule by an Islamic jurist.

The revolution had a profound impact on the Middle East and led to a long-standing hostile relationship between Iran and the United States.