On November 4, 1979, members of the Muslim Student Followers of the Imam's Line stormed and occupied the U.S. Embassy in Tehran, taking 66 Americans hostage. The action followed months of upheaval after the Iranian Revolution and was fueled by anger over the Carter administration's decision to admit the exiled Shah, Mohammad Reza Pahlavi, into the United States for cancer treatment. The hostage-takers, who received the public backing of Ayatollah Ruhollah Khomeini, demanded the Shah be extradited to Iran to stand trial. Six American diplomats evaded capture and hid in the homes of Canadian diplomats before being smuggled out of the country on January 28, 1980, in the covert operation known as the "Canadian Caper."
Of the original 66 hostages, 13 women and African American staff were released in November 1979, and one more hostage, Richard Queen, was freed in July 1980 after developing what was later diagnosed as multiple sclerosis. The remaining 52 hostages were held for the duration of the crisis. According to accounts, hostages reported beatings, theft, prolonged solitary confinement, being bound for extended periods, mock executions, and threats of violence against themselves and their families. Some hostages attempted escape or self-harm during their captivity, and living conditions shifted over time as hostages were moved among the Foreign Ministry, various prisons, and finally the Teymur Bakhtiar mansion in Tehran.
President Jimmy Carter responded with economic pressure, ending oil imports from Iran and freezing an estimated $8 billion in Iranian assets in the United States. A military rescue attempt, Operation Eagle Claw, was launched on April 24, 1980, but failed in the Iranian desert after mechanical and weather-related problems; eight U.S. servicemen were killed in an accident during the operation's abort phase, and one Iranian civilian also died. The failure led to the resignation of Secretary of State Cyrus Vance and further damaged Carter's political standing ahead of the 1980 presidential election, which he lost.
The crisis was ultimately resolved through Algerian mediation. In late 1980, the Iranian parliament set conditions for release, including the unfreezing of Iranian assets, and negotiations culminated in the Algiers Accords. The 52 remaining hostages were released on January 20, 1981, minutes after Ronald Reagan's presidential inauguration, ending 444 days of captivity. The Shah had died in Cairo, Egypt, on July 27, 1980, before the crisis concluded. The events significantly damaged U.S.-Iran relations for decades and, within Iran, strengthened Khomeini's political authority and that of theocratic factions opposed to normalizing relations with the West.