1906

New constitution limits monarchy

Widespread protests by clerics and merchants against the shah's mishandling of revenues and the foreign domination of Iranian assets leads to the Constitutional Revolution. The shah signs the new constitution in December, which effectively limits royal power and establishes an elected parliament, or Majlis.

1907

Russia, Britain define 'spheres of influence'

The Anglo-Russian Agreement between Russia and Britain divides Iran into spheres of influence, challenging Iran's moves toward independence.

1919

Britain extends influence

Britain draws up a plan to extend its influence over all of Iran, which would effectively make it a British protectorate. The agreement rouses fierce opposition in Iran's Parliament, however, and it is never ratified.

1921-1926

Qajar Dynasty collapses; Pahlavi Dynasty begins

An Iranian officer of the Persian Cossacks Brigade, Reza Khan, wrests power away from the constitutional government, signaling an end to the Qajar Dynasty. He becomes prime minister in 1923, and proclaims himself the first shah of the new Pahlavi Dynasty in 1925. The official coronation takes place in 1926, at which time the shah's eldest son, Mohammad Reza, is proclaimed crown prince.

1941

Shah Pahlavi abdicates throne

Pressure from Britain and the Soviets forces Shah Reza Pahlavi, who they see as sympathetic to the Nazi regime in Germany, to abdicate his throne. His son, Mohammad Reza Pahlavi, becomes shah. Allied forces are then able to occupy Iran and transport munitions to Russia to push back the Nazi advances.

1951

Nationalist PM Mossadeq begins reign

The day after the assassination of Iranian Premier Ali Razmara, who was sympathetic to the West, the new prime minister, Mohammad Mossadeq, submits to Iran's Parliament a plan to nationalize the country's oil assets. Throughout the next couple of years, Mossadeq moves to limit foreign interests in Iran and to limit the shah's powers.

1953

U.S.-backed coup ousts Mossadeq; reinstates shah

At the height of the Cold War, the Eisenhower administration approves a joint British-American operation to overthrow Mossadeq, worried that his nationalist aspirations will lead to an eventual communist takeover. The operation is code-named Operation Ajax. At first, the military coup seems to fail, and the shah flees the country. After widespread rioting -- and with help from the CIA and British intelligence services -- Mossadeq is defeated and the shah returns to power, ensuring support for Western oil interests and snuffing the threat of communist expansion. General Fazlollah Zahedi, who led the military coup, becomes prime minister.

1963

The 'White Revolution' and Ayatollah Khomeini

The shah introduces his "White Revolution," a package of comprehensive social and economic reforms that aim to modernize the country. He also announces that he is extending the right to vote to women.

The clerical establishment is outspoken against the White Revolution, leading the shah to clamp down on its opponents. Ayatollah Ruhollah Khomeini, a leading cleric in the religious city of Qom, is arrested after he harshly criticizes the shah. His arrest incites demonstrations, which are quelled by the shah's security forces.

1964

Khomeini exiled

Khomeini is exiled to Turkey for his outspoken denunciation of the shah's Status of Forces bill, which grants U.S. military personnel diplomatic immunity for crimes committed on Iranian soil. From Turkey, Khomeini moves to Iraq in 1965 and remains there until 1978. (Though Iraq is largely Sunni, Khomeini resides in An Najaf, which is home to many Shiite shrines.)

1978

Pro-Khomeini demonstrations; revolution looms

In January, an article in an Iranian newspaper smears Khomeini, leading to the outbreak of violent demonstrations in Qom. The unrest spreads throughout the country. In September, in what is known now as Black Friday, government troops fire on demonstrators. Martial law is declared.

Baghdad, under pressure from Tehran, forces Khomeini to leave, and he settles in Paris where he establishes an opposition movement in exile. The Islamic Revolutionary Council, an underground assembly, is formed in Iran at Khomeini's behest.

January-
February
1979

The Iranian Revolution triumphs

In January, as civil rest increases, the shah and his family are forced into exile. On Feb. 1, Khomeini returns after nearly 15 years in exile and is given a triumphant welcome in Tehran. That same month, the shah's military announces its neutrality, and the monarchy collapses. With Mehdi Bazargan as prime minister, Khomeini takes power and proclaims the Islamic Republic of Iran in April.

October-
November
1979

Shah enters U.S.; Embassy in Tehran seized

In October, over the objections of Iran's revolutionary government, the U.S. allows the shah to enter the country in order to obtain treatment for cancer. On November 4, militant students seize the compound of the U.S. Embassy in Tehran, demanding that the U.S. send the shah back to Iran so that he can stand trial. Thus begins the crisis in which 52 Americans are held hostage for 444 days. U.S. President Jimmy Carter orders a complete embargo of Iranian oil, with tougher sanctions to follow.

December
1979

Iran's Constitution ratified; Velayat-e faqih codified

Iran's Constitution is ratified by national referendum. It is based upon velayat-e faqih, or the rule of the Islamic jurist. It establishes a religious authority, the Supreme Leader, who has ultimate authority.

January
1980

Bani-Sadr elected Islamic Republic's first president

Abolhassan Bani-Sadr is elected the first president of the Islamic Republic of Iran. Khomeini, as Supreme Leader, still has ultimate control of the new government.

April
1980

U.S. severs relations, attempts hostage rescue

In early April, U.S. President Jimmy Carter severs diplomatic relations with Iran after negotiations to free the hostages fail. He authorizes a top-secret mission, named Operation Eagle Claw, to free the hostages. The complicated mission is aborted after three of the eight helicopters to be used in the rescue suffer mechanical failure. Eight U.S. servicemen are killed when one of the helicopters collides with a refueling plane.

July
1980

Shah dies

The exiled shah dies in Egypt.

September
1980

Iraq invades Iran

Iraq invades Iran and launches strategic airstrikes. The war rages for 8 years, killing millions; it is longest conventional war of the 20th century. Though the U.S. supplies weapons to both sides over the course of the conflict, it mostly favors Iraq, which leads to further resentment in Iran.

1981

Hostages released; Khamenei becomes president

After intense negotiations, the remaining hostages are released just minutes after Ronald Reagan is sworn in as U.S. president in January.

Bani-Sadr, after increasing clashes with Khomeini, is impeached by a vote of 177-1 in Parliament. His successor, Mohammad Ali Rajai, perishes in the second of two bombings targeting high-level government officials. The prime minister and dozens of members of Parliament are also killed. The government blames the attacks on Mujahedeen-e Khalq, a socialist opposition movement that turned against the revolutionary government after its influence was markedly diminished in the new power structure.

Following Rajai's death, Ali Khamenei is elected the third president of Iran in October.

1982

Iran in Lebanon's Bekaa Valley

Israel invades Lebanon, prompting Iran to deploy its Islamic Revolutionary Guard Corps (Revolutionary Guards) to the Bekaa Valley. Iran resolves to help the Lebanese Muslims fight against the invasion, and objects to what it says is U.S. support for Israel's actions.

In July, operatives from the American-backed Lebanese Christian forces kidnap four Iranian diplomats -- including the commander of the Revolutionary Guards in the Bekaa and the Iranian charge d'affaires. Retaliatory kidnappings follow, thus inaugurating nine years in which dozens of Westerners are taken hostage. The first hostage is David Dodge, an American who is the acting president of the American University in Beirut. U.S. officials believe that operatives from the Iranian-backed Shiite group Hezbollah, based in Lebanon, is behind most of the kidnappings.

1983

Attacks on U.S. Embassy, Marine barracks in Beirut

In April, a suicide bomber in a pickup truck loaded with explosives rams into the U.S. Embassy in Beirut, Lebanon. Seventeen Americans are among the 63 people who are killed, eight of whom are employees of the CIA, including chief Middle East analyst Robert C. Ames and station chief Kenneth Haas. The Reagan administration blames Hezbollah, which it suspects receives financial and logistical support from both Iran and Syria. [For more on how and why Iran and Syria were helping to direct attacks on the U.S., see FRONTLINE's interviews with Robert Oakley and Robert C. McFarlane.]

In October, a suicide bomber detonates a truck full of explosives at a U.S. Marine barracks at Beirut International Airport; 241 U.S. Marines are killed and more than 100 others wounded. The soldiers are part of a contingent of 1,800 Marines that had been sent to Lebanon to help separate the warring Lebanese factions. In his September 2001 FRONTLINE interview, former Secretary of Defense Caspar Weinberger says that the U.S. still lacks "actual knowledge of who did the bombing" of the Marine barracks, but it suspects Hezbollah.

1984

Second U.S. Embassy bombing; U.S. warms to Iraq

In September, a truck bomb explodes outside the U.S. Embassy annex northeast of Beirut, killing 24 people, two of whom are U.S. military personnel. According to the U.S. State Department's 1999 report on terrorist organizations, elements of Hezbollah are "known or suspected to have been involved" in the bombing.

In November, the United States again establishes diplomatic relations with Iraq, which had been severed after the 1967 Arab-Israeli war.

1985

Khamenei reelected; Montazeri named Khomeini's successor

Khamenei is reelected president in national elections. The Assembly of Experts designates Ayatollah Hosein-Ali Montazeri as Khomeini's heir apparent.

1985-1986

The Iran-Contra affair

In an attempt to end the Lebanese hostage crisis, U.S. officials, who believed that Iranian-backed operatives of Hezbollah were responsible for the kidnappings, devised a covert plan. Iran was desperately running out of military supplies in its war with Iraq, and Congress had banned the sale of American arms to countries that it said sponsored terrorism, which included Iran. U.S. President Ronald Reagan was advised that a bargain could be struck -- secret arms sales to Iran, hostages back to the U.S. The plan, when it was revealed to the public, was decried as a failure and anathema to the U.S. policy of refusing to negotiate with terrorists.

In August 1985, the first consignment of arms -- 100 anti-tank missiles provided by Israel -- was sent to Iran. Hundreds more were sent the following month. Three hostages were released as a result of the arms-for-hostages deal.

Since the funds from the arms sales to Iran were secretly, and illegally, funneled to the U.S.-backed Contras fighting to overthrow the Sandinista regime in Nicaragua, the episode became known as the "Iran-Contra affair." It would amount to the biggest crisis in Ronald Reagan's presidency. (See the "Final Report of the Independent Counsel for Iran/Contra Matters.")

July 3,
1988

USS Vincennes shoots down passenger plane

The American Navy cruiser USS Vincennes mistakenly shoots down an Iranian passenger plane in the Gulf, killing all 290 people aboard. A sober Reagan announces that the U.S. deeply regrets the mistake, but Iran sees it as evidence that the U.S. planned to get involved in the war against Iraq.

July 18,
1988

Iran, Iraq sign cease-fire agreement

Ayatollah Khomeini accepts a U.N.-brokered cease-fire agreement ending the war with Iraq.

February
1989

Khomeini issues fatwa against Salman Rushdie

Supreme Leader Khomeini issues a fatwa (religious decree) ordering the death of British author Salman Rushdie. He considers Rushdie's novel The Satanic Verses blasphemous to Islam.

June-
July
1989

Khamenei succeeds Khomeini as Supreme Leader

In early June, Khomeini dies of a heart attack. The Assembly of Experts chooses President Ali Khamenei as Supreme Leader. (Three months earlier, Ayatollah Montazeri had lost his designation as Khomeini's successor because of his outspoken criticism of the regime.)

In July, Khamenei is confirmed as Supreme Leader and Ali Akbar Hashemi Rafsanjani, the speaker of Parliament, is elected president.

1990-1991

Persian Gulf War

Iran remains neutral in U.S.-led war against Saddam Hussein. It denounces both Baghdad's occupation of Kuwait, and the possibility of a long-term U.S. military presence in the region.

1993

Rafsanjani reelected; U.S. 'dual containment' policy

Rafsanjani is again elected president. In the U.S., President Bill Clinton takes office and soon defines his administration's policy of "dual containment," the effort to isolate Iran for its alleged support of terrorist activities, its pursuit of nuclear weapons, and its efforts to undermine Middle East peace efforts.

April
1995

Clinton signs trade embargo

Clinton signs an executive order banning trade with Iran.

March-
April
1996

Conservatives solidify control of Iran's Parliament

In the nationwide elections held in March and April, conservatives in Iran solidify their control of Parliament

June
1996

Khobar Towers bombing

On June 25 in Dhahran, Saudi Arabia, a truck bomb explodes outside the Khobar Towers, which are home to nearly half of the 5,000-member U.S. military force in Saudi Arabia. Nineteen U.S. servicemen are killed and more than 500 others are injured, 240 of which are American.

A shadowy terrorist organization known as Saudi Hezbollah is publicly named. It is linked both to Lebanon's Hezbollah and to "Iranian officials" who helped direct the organization's terrorist efforts. In June 2001, a federal grand jury indicts 13 Saudis and a Lebanese for the bombing, saying they were given support by Iran.

August
1996

U.S. levies more sanctions against Iran

The U.S. Congress passes the Iran-Libya Sanctions Act, which sanctions companies that invest $40 million or more annually in oil and gas projects in Iran or Libya. The European Union challenges the law's validity.

1997

Khatami elected in landslide win

In May 1997, Iranians go to the polls in droves to cast their ballots in the presidential election. Nearly 80 percent of eligible voters participate, and fully 70 percent of them vote for Mohammad Khatami, the moderate cleric and former minister of culture and Islamic guidance. His victory stuns the clerical establishment, whose own candidate, Speaker of Parliament Ali Akbar Nateq-Nouri, was considered the inevitable winner. A longtime advocate for press freedom and individual liberties, Khatami promises to restore the rule of law to Iran.

In the U.S., President Clinton calls Khatami's election a "hopeful sign," but repeats his previous position that relations between the U.S. and Iran cannot be restored until Iran denounces terrorism, ceases opposition to U.S.-led Middle East peace efforts, and stops seeking nuclear weapons.

In August of 1997, Supreme Leader Khamenei confirms Khatami as the fifth president of the Islamic Republic of Iran.

1998

Khatami, Albright signal a warming of relations

In an interview with CNN's Christiane Amanpour in January, Khatami proposes cultural exchanges between the U.S. and Iran in order to "crack the wall of mistrust." However, he dismisses the need for official government-to-government dialogue.

In June, Secretary of State Madeleine Albright invites Iranians to join with the U.S. to draw up a "road map leading to normal relations."

February
1999

Reformers win in municipal elections

The same month that the Islamic Republic celebrates its 20th anniversary, Iranians go to the polls to fill 190,000 vacancies in city councils and other municipal offices across the country. As expected, reformist candidates win nationwide, overwhelmingly, and secure 12 of the 15 seats in Tehran alone.

March
1999

Khatami visits Italy

Khatami visits Italy in March, the first trip to a Western country by an Iranian leader in two decades.

July
1999

Student demonstrations lead to widespread unrest; U.S. eases sanctions

Responding to the closing of a popular reformist newspaper and a law proposed by Parliament that would limit press freedom, students stage six days of demonstrations across the country in July. The students clash with hard-liners and the police, and the violence escalates. There are reports of widespread police brutality against the students. More than 1,000 people are arrested in the worst unrest since the revolution.

That same month, the U.S. eases sanctions and allows American companies to sell food and medical items to three countries that the U.S. State Department has branded as state supporters of terrorism -- Iran, Libya, and Sudan.

October
1999

Popular reformer imprisoned

Just months in advance of the parliamentary elections, the Special Clerical Court -- a tribunal that tries clerics for crimes against the Islamic Republic -- charges Abdullah Nouri with spreading anti-Islamic propaganda. A former Interior minister, Nouri is one of the country's leading reformers and a key Khatami ally. The trial captivates the nation. He is subsequently sentenced to five years in prison.

February
2000

Reformers take control of Parliament

In the wake of Nouri's trial, the 2000 parliamentary elections are held, the sixth since the Republic's founding. More than 5,000 people declare their candidacy for the 290 seats. When the elections are held in mid-February, voter turnout is, once again, overwhelming: 70 percent of qualified voters cast their ballots. Reformist candidates rout the conservatives, claiming 70 percent of the seats. Former President Rafsanjani finishes a humiliating 30th in Tehran, barely capturing the last of the city's seats in Parliament. (He subsequently relinquishes his seat.)

Only 14 percent of the new deputies in Parliament are clerics. In 1980, they comprised more than half of the first Parliament. It marks the first time that the reformists win an absolute majority of seats in Parliament. Two of the three branches of government -- the executive and legislative -- are controlled by reformists.

March
2000

U.S. acknowledges role in 1953 coup

Secretary of State Madeleine Albright acknowledges the U.S. role in the 1953 coup that overthrew Mossadeq, but stops short of an apology. The U.S. lifts sanctions on Iranian luxury goods.

May
2000

World Bank approves loans to Iran

Over U.S. objections, the World Bank approves its first loans to Iran in seven years.

June
2000

Report faults Clinton administration on Khobar investigation

The National Commission on Terrorism releases a report that says the Clinton administration had not acted aggressively enough and did not place enough diplomatic pressure on Iran to force its leaders to cooperate in the investigation of the Khobar Towers bombing.

April
2001

Saudi Arabia, Iran sign security agreement

Saudi Arabia and Iran sign a security agreement, signaling a thaw in relations between Iran and other Arab countries that suspect it of fomenting Shiite dissent.

June
2001

Khatami reelected

On June 8, Khatami wins the presidential election by a landslide, securing nearly 80 percent of the popular vote. His dominating victory adds to the credibility of the reform movement and raises expectations.

A showdown between Supreme Leader Khamenei and Parliament delays Khatami's inauguration. In August, three days later than originally scheduled, Khatami is finally inaugurated. The New York Times describes his inaugural address as "assertive." He acknowledges, briefly, the previous years' setbacks for the reform movement, and tries to stay above the political fray. "I will not paint my critics and opponents as those opposed to Islam, the revolution, freedom, or people," Khatami said, "but will value their lawful presence, and will respect them and avoid insulting their dignity."

June
2001

Khobar indictment implicates unidentified Iranians

After a five-year investigation, U.S. Attorney General John Ashcroft releases details of the 46-count indictment from the Khobar Towers case. Ashcroft says that unidentified Iranians "inspired, supported, and supervised" the suspects, who belonged to a group the indictment identified as Saudi Hezbollah. Iran flatly rejects the accusation that it was involved in the bombing.

July
2001

U.S. Senate extends sanctions for five years

The U.S. Senate gives final congressional approval to legislation that extends the sanctions against Iran and Libya for five years. The Bush administration had pressed Congress to limit the sanctions to two years.

October
2001

Conflicting messages from Iran on U.S. strikes in Afghanistan

Supreme Leader Khamenei condemns the U.S. strikes on Afghanistan, saying they are part of America's goal to "expand their power and domination." Meanwhile, news reports surface that Iran has agreed to perform search-and-rescue missions for U.S. pilots who crash on Iranian soil during the military strikes against the Taliban in Afghanistan.

October
2001

Iran, Russia sign military accord

In October, six years after it ceased arms sales to Iran because of U.S. pressure, Russia signs a military accord with Iran. The agreement could lead to $300 million in sales of jets, missiles, and other weapons. U.S. officials are strongly opposed to the arms sales, citing the State Department's designation of Iran as a state-sponsor of terrorism.

November
2001

Khatami denounces bin Laden's followers

In his first interview with an American publication, Khatami tells The New York Times in November that Osama bin Laden's version of Islam does not represent the majority view of the world's Muslims. "The horrific terrorist attacks of Sept. 11, 2001, in the United States were perpetrated by [a] cult of fanatics who had self-mutilated their ears and tongues, and could only communicate with perceived opponents through carnage and devastation." He also rejected outright U.S. charges that Iran supports terrorism, saying, "This is one of the injustices of the U.S. against us."

November
2001

Powell and Kharrazi shake hands at U.N.

U.S. Secretary of State Colin Powell and Iranian Foreign Minister Kamal Kharrazi shake hands at U.N. headquarters in New York, where foreign ministers from Russia, the U.S., and Afghanistan's neighbors are meeting to discuss a post-Taliban government. A report in The New York Times indicates that the gesture is considered "a significant step forward in relations that have been officially frozen since the Iranian revolution of 1979."

January
2002

Ship carrying arms to Palestinian Authority seized

Israeli commandos seize the Karine A, a ship carrying 50 tons of arms that officials say were supplied by Iran and en route to the Palestinian Authority. Officials say that the delivery of weapons -- which include powerful Katyusha rockets, antitank missiles, and plastic explosives -- would escalate the Palestinian-Israeli conflict to a new level.

January-
March
2002

'Axis of evil' and its aftermath

In his first State of the Union address, U.S. President George W. Bush says that Iran, Iraq, and North Korea are part of an "axis of evil." "Iran aggressively pursues these weapons [of mass destruction] and exports terror, while an unelected few repress the Iranian people's hope for freedom," Bush says.

The speech outrages some in Iran, sparking protests. It is condemned both by the clerical establishment and the reformers. Recent calls for reform from parliamentary leaders, however, have invoked Bush's indictment of the "unelected few."

"Reforming the Expediency Council is in line with the people's demand for change, which they have voiced in various elections in the past five years," said Mohammad Reza Khatami, the deputy speaker of Parliament and President Mohammad Khatami's brother, as reported in The New York Times in March 2002. "It would not only be a step toward national unity but also a response to the president of United States, who distinguished between elected and nonelected institutions in Iran."

March
2002

Iran responds to U.S. Senate offer

Iran's government spokesman says that Iran will not oppose direct talks with American legislators. It is in response to an offer made by Sen. Joseph Biden (D-Del.), chairman of the Senate Foreign Relations Committee, to meet Iranian deputies. Biden says that White House staff was "complementary" of his efforts to engage the Iranians. "I won't call it backpedalling, because that's pejorative," Biden tells FRONTLINE. "But I think there was a refinement of what they meant by it ["axis of evil"]."

April
2002

Rumsfeld denounces Iran's alleged role in West Bank

U.S. Secretary of Defense Donald Rumsfeld links three countries -- Iran, Iraq, and Libya -- to suicide bombing attacks in Israel and says that the countries are "inspiring and financing a culture of political murder and suicide bombing."

May
2002

Khamenei calls negotiations with the U.S. useless

Iran's Supreme Leader, Ayatollah Ali Khamenei, denounces the U.S. and dismisses the idea of negotiations between the two countries, saying, "Negotiations will not solve any problem. Negotiations with America are beneficial to the American government." A report in Financial Times, however, indicates that reformist leaders continue to press for an opening up of relations, and that an internal debate persists over whether and how to engage the U.S.