The "Shah of Iran" refers to the monarch who ruled Iran before the 1979 Iranian Revolution. The last Shah, Mohammad Reza Pahlavi, ascended to the throne in 1941 and implemented various modernization and secularization reforms, known as the White Revolution. His reign faced opposition from various groups, including religious leaders and leftist movements. In 1979, widespread protests led to the Shah's exile and the establishment of the Islamic Republic of Iran under Ayatollah Khomeini. The revolution marked a significant shift in Iran's political landscape, transitioning from a monarchy to a theocratic regime, fundamentally altering the country's governance and society.