Demonstrations against the Shah commenced in October 1977, developing into a campaign of civil resistance that included both secular and religious elements,[8][9][10] and which intensified in January 1978.[11] Between August and December 1978, strikes and demonstrations paralyzed the country. The Shah left Iran for exile on 16 January 1979, as the last Persian monarch, leaving his duties to a regency council and Shapour Bakhtiar who was an opposition-based prime minister. Ayatollah Khomeini was invited back to Iran by the government,[12][13] and returned to Tehran to a greeting by several million Iranians.[14] The royal reign collapsed shortly after on 11 February when guerrillas and rebel troops overwhelmed troops loyal to the Shah in armed street fighting, bringing Khomeini to official power.[15][16] Iran voted by national referendum to become an Islamic republic on 1 April 1979[17] and to formulate and approve a new theocratic-republican constitution[8][9][18][19] whereby Khomeini became Supreme Leader of the country in December 1979.
The revolution was unusual for the surprise it created throughout the world:[20] it lacked many of the customary causes of revolution (defeat at war, a financial crisis, peasant rebellion, or disgruntled military),[21] occurred in a nation that was experiencing relative prosperity,[12][19] produced profound change at great speed,[22] was massively popular, resulted in the exile of many Iranians,[23] and replaced a pro-Western authoritarian monarchy[12] with an anti-Western totalitarian theocracy[12][18][19][Note 1][25] based on the concept of Guardianship of the Islamic Jurists (or velayat-e faqih). It was a relatively non-violent revolution, and it helped to redefine the meaning and practice of modern revolutions (although there was violence in its aftermath).[26]
Reasons advanced for the revolution and its populist, nationalist and, later, Shi'a Islamic character include a conservative backlash against the Westernizing and secularizing efforts of the Western-backed Shah,[27] a rise in expectations created by the 1973 oil revenue windfall and an overly ambitious economic program, anger over a short, sharp economic contraction in 1977–78,[Note 2] and other shortcomings of the previous regime.
The Shah's regime was seen as an oppressive, brutal,[32][33] corrupt, and extravagant regime by some of the society classes at that time.[32][34] It also suffered from some basic functional failures that brought economic bottlenecks, shortages, and inflation.[35] The Shah was perceived by many as beholden to – if not a puppet of – a non-Muslim Western power (the United States)[36][37] whose culture was affecting that of Iran. At the same time, support for the Shah may have waned among Western politicians and media – especially under the administration of U.S. President Jimmy Carter – as a result of the Shah's support for OPEC petroleum price increases earlier in the decade.[38] When President Carter enacted a human-rights policy which said countries guilty of human-rights violations would be deprived of American arms or aid, this helped give some Iranians the courage to post open letters and petitions in the hope that the repression by the government might subside.[39]
The revolution that replaced the monarchy of Mohammad Reza Shah Pahlavi with Islamism and Khomeini, rather than with another leader and ideology, is credited in part to the spread of the Shia version of the Islamic revival that opposed Westernization and saw Ayatollah Khomeini as following in the footsteps of the Shi'a Imam Husayn ibn Ali and the Shah in the role of Husayn's foe, the hated tyrant Yazid I.[40] Other factors include the underestimation of Khomeini's Islamist movement by both the Shah's reign – who considered them a minor threat compared to the Marxists and Islamic socialists[41][42][43] – and by the secularist, opponents of the government – who thought the Khomeinists could be sidelined.[44]
