The last Shah of Iran, Mohammed Reza Pahlavi, was forced to abdicate in 1941 due to his alliance with Germany, allowing his son Mohammad Reza to assume the throne. Mohammad Reza advocated reforms like land reform, women's suffrage, and literacy elimination. He was a major US ally, ruling with a hard hand relying on the SAVAK secret police. Facing growing unrest, the Shah went into exile in 1979 and an Islamic republic led by Ayatollah Khomeini took power, establishing an Islamic regime that rejected Western influence. Khomeini's rise to power was followed by the Iran hostage crisis where US embassy staff were held for 444 days.