The significant event in Iran's history that marked a shift to Islamic governance in 1979 was the Iranian Revolution. This revolution overthrew the Pahlavi monarchy, led by Shah Mohammad Reza Pahlavi, and established an Islamic Republic under Ayatollah Khomeini. The revolution was notable for its popular support, marked by a coalition of various social groups, including religious clerics and leftist factions opposing Western influence. This transformation profoundly affected Iran’s domestic policies and had vast implications for regional dynamics, affecting relations with Western nations and influencing Islamic movements globally.