1978 - Shah Mohammed Reza Pahlavi's authoritarian rule sparks demonstrations and riots.
February 1, 1979 - Ayatollah Ruhollah Khomeini returns to Iran, after 14 years in exile, to lead the country.
October 22, 1979 - The Shah is allowed to enter the United States to receive medical treatment for cancer.
November 4, 1979 - Iranian students demonstrating outside of the US embassy in Tehran storm the embassy and take 90 people hostage including 66 Americans. The students demand the extradition of the Shah from the United States. Ayatollah Khomeini issues a statement of support for the students' actions.
November 5, 1979 - The Iranian government cancels military treaties with the US and the Soviet Union, treaties that would permit US or Soviet military intervention.
November 6, 1979 - Premier Mehdi Bazargan and his government resign, leaving Ayatollah Khomeini and the Revolutionary Council in power.
November 7, 1979 - US President Jimmy Carter sends former Attorney General Ramsey Clark and Senate Intelligence Committee staff director William Miller to Iran to negotiate the release of the hostages. Ayatollah Khomeini refuses to meet with them.
November 14, 1979 - President Carter orders Iranian assets in US banks frozen.
November 17, 1979 - Khomeini orders the release of female and African-American hostages. They are released November 19 and 20, bringing the total number of US hostages to 53.
December 4, 1979 - The United Nations Security Council passes a resolution calling for Iran to release the hostages.
December 15, 1979 - The Shah leaves the United States for Panama.
January 28, 1980 - Six American embassy employees, who avoided capture and hid in the homes of Canadian Embassy officers, flee Iran. In 1997 it is revealed that, along with the