Final answer:
The Iranian Revolution of 1979 overthrew the pro-Western Shah, led to Ayatollah Khomeini's rise to power, and established an Islamic republic. The nationalization of the oil industry and the US embassy hostage crisis had profound effects on Iran's relations with the West.
Step-by-step explanation:
The Iranian Revolution of 1979 was a transformative event that saw the fall of the Shah of Iran, who was supported by the United States, and the rise to power of the Muslim religious leader Ayatollah Khomeini. Anti-Western sentiment had been building up in Iran due to the Shah's policies of westernization and close ties with the US.
Khomeini's return from exile sparked a series of demonstrations and strikes, which led to a revolution. On November 4, 1979, Iranian students stormed the US embassy in Tehran, taking 52 Americans hostage and signalling a major shift in Iran's political landscape towards an Islamic republic.
Protests against the Shah began to intensify when the Muslim clergy called for a large public prayer on the end of Ramadan. The Shah's reaction of declaring martial law resulted in the tragic deaths of demonstrators, which further fueled the uprising.
By December 1979, Iranians voted to adopt a new constitution establishing an Islamic republic, with Islam as the official religion, and ensuring that laws conformed to Islamic principles.
The revolution had significant consequences, including the nationalization of the oil industry previously under Western control, which contributed to the global energy crisis.
The relationship between Iran and the US was severely affected, especially after the hostage crisis, and the shift towards an Islamic republic marked a departure from the secular and Western orientation of the Shah's regime.