A look at important dates in Iranian international and domestic affairs since the 1979 Islamic Revolution.
_ February 1979: Forces loyal to Ayatollah Ruhollah Khomeini oust the Western-backed shah.
_ Nov. 4, 1979: Iranian students storm the U.S. Embassy in Tehran and take dozens of hostages after U.S. refuses to deport the shah, who was in the United States for cancer treatment.
_ April 24, 1980: An attempt by U.S. commandos to free the hostages ends in failure when a helicopter crashes into C-130 transport plane in Iranian desert, killing eight American servicemen.
_ September 1980: Iraqi forces invade Iran, beginning an eight-year war that claims an estimated 1 million lives._ January 1981: Iran releases the American hostages; fifty-two Americans held for 444 days inside embassy compound.
_ 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: Khomeini dies. Ayatollah Ali Khamenei is later selected as supreme leader.
_ May 1997: Pro-reform cleric Mohammad Khatami wins presidential elections, beginning demands for greater social and political freedoms.
_ June 2001: Khatami re-elected.
_ January 2002: President George W. 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.
_ April 2006: Iran announces it has successfully enriched uranium on small scale.
_ May 2008: UN Security Council passes resolution requiring Iran to halt uranium enrichment. Iran has ignored the order.
_ March 20: President Barack Obama releases video message for Iranian New Year calling for dialogue with Iran's leaders.