Provided by the Associated Press and posted on the Seattle Post Intelligencer
- April 1951: Mohammed Mossadegh is elected prime minister and nationalizes oil interests. In June 1953, the Eisenhower administration approves a British proposal for a joint Anglo-American operation, code-named Operation Ajax, to overthrow Mossadegh. His toppling becomes a long-standing source of resentment among Iranians toward the U.S.
- 1970: Iran signs the Nuclear Non-Proliferation Treaty.
- February 1979: Ayatollah Ruhollah Khomeini leads a revolution that ousts the shah and creates the Islamic Republic of Iran. In October, President Jimmy Carter allows the exiled shah into the U.S. for medical treatment.
- Nov. 4, 1979: Iranian students occupy the U.S. embassy. Fifty-two American hostages are held for 444 days in response to Carter's refusal to send the shah back to Iran for trial...
- April 24, 1980: An attempt by U.S. commandos to free hostages ends in failure when helicopter crashes into C-130 transport plane in Iranian desert, killing eight American servicemen.
- July 27, 1980: The shah dies of cancer in Egypt.
- January 1981: Iran releases the American hostages.
- 1986: United States sells arms to Iran in secret deal aimed at helping win release of American hostages held by Shiite militias in Lebanon.
- July 3, 1988: The USS Vincennes in the Gulf mistakenly shoots down an Iranian commercial jet, killing 290 passengers and crew.
- June 3, 1989: Ayatollah Khomeini dies four months after issuing a fatwa, or religious ruling, ordering Muslims to kill British author Salman Rushdie because of his book The Satanic Verses, judged blasphemous to Islam.
- 1995: U.S. imposes oil and trade sanctions on Iran, saying it sponsors terrorism, is seeking to acquire nuclear weapons and is hostile to the Mideast peace process.
- May 1997: Pro-reform cleric Mohammad Khatami wins presidential elections on platform of easing social restrictions and improving ties with West, including United States. Khatami is re-elected in June 2001 but faces mounting pressure from conservatives.
- January 2002: In his State of the Union address, President Bush describes Iran, Iraq and North Korea as "the axis of evil."
- September 2004: Secretary of State Colin Powell says Iran's nuclear program is a growing threat and calls for international sanctions.
- June 2005: Hard-liner Mahmoud Ahmadinejad is elected president, sealing downfall of reform movement, vows to continue nuclear program, insisting it is peaceful.
- April 2006: Iran announces it has successfully enriched uranium on small scale.
- May 2006: Britain and France, backed by United States, propose Security Council resolution demanding Iran abandon uranium enrichment or face the threat of unspecified further measures, a possible reference to sanctions.