Mohammad Rezā Shāh Pahlavi, Shah of Iran, Shah of Persia (Persian: محمدرضا شاه پهلویr ; [mohæmˈmæd reˈzɒː ˈʃɒːhe pæhlæˈviː]; 26 October 1919 – 27 July 1980), ruled Iran from 16 September 1941 until his overthrow by the Iranian Revolution on 11 February 1979. He was the second and last monarch of the House of Pahlavi of the Iranian monarchy. Mohammad Reza Shah Pahlavi held several titles: His Imperial Majesty, Shahanshah (King of Kings, Emperor), Aryamehr (Light of the Aryans) and Bozorg Arteshtārān (Head of the Warriors, Persian: بزرگ ارتشتاران).
The young prince came to power during World War II after an Anglo-Soviet invasion forced the abdication of his father Reza Shah. His rule oversaw the nationalization of the Iranian oil industry under the prime ministership of Mohammad Mosaddegh. During the Shah's reign, Iran marked the anniversary of 2,500 years of continuous monarchy since the founding of the Persian Empire by Cyrus the Great. His White Revolution – a series of economic and social reforms intended to transform Iran into a global power – succeeded in modernizing the nation, nationalizing many natural resources and extending suffrage to women.
A Secular Muslim himself, the Shah gradually lost support from the Shi'a clergy of Iran, particularly due to his strong policy of modernization, secularization and conflict with the traditional class of merchants known as bazaari, and recognition of Israel. Clashes with the Islamists, increased communist activity and a 1953 period of political disagreements with Mohammad Mosaddegh – eventually leading to Mosaddeq's ousting – caused the Shah's opponents to disagree and overthrow his rule.
Various controversial policies were enacted, including the banning of the communist Tudeh Party and a general suppression of political dissent by Iran's intelligence agency, SAVAK. Amnesty International reported that Iran had as many as 2,200 political prisoners in 1978. By 1979, political unrest had transformed into a revolution which, on 16 January, forced the Shah to leave Iran. Soon thereafter, the former Iranian government of the Shah was transformed into an Islamic republic.