Dec. 25, 1979 To prop up a leader that it favors, the Soviet Union invades Afghanistan.

1980 Soviets install their puppet, Babrak Karmal, as ruler of Afghanistan. Resistance intensifies as various groups battle the Soviets. The U.S., Pakistan, China, Iran and Saudi Arabia supply money and arms to anti-Soviet forces. Funneling the funds through the CIA, the U.S. gives about $10 billion to Afghan fighters. Among those who fight is Osama bin Laden, son of a wealthy Saudi Arabian construction magnate.

1985 New Soviet leader Mikhail Gorbachev pledges to withdraw troops from Afghanistan.

1986 The U.S. begins supplying mujahadeen groups with surface-to-air missiles, which enables them to shoot down Soviet helicopters.

1988 After Afghanistan, the USSR, the U.S. and Pakistan sign a peace treaty, the Soviet Union begins pulling out troops.

1989 The last Soviet troops withdraw. Over the previous nine years, 13,000 Soviet troops have been killed. Mujahadeen soon overthrow the Soviet puppet, but continue to fight among themselves for control of the country.

1990 The Gulf War and the flow of foreign troops into the Middle East fuel bin Laden's anger against the U.S.

1991 Saudis arrest bin Laden for criticizing their decision to bring in American troops. He leaves for Sudan and begins setting up terrorist training camps.

1993 According to U.S. officials, bin Laden is the mastermind behind the bomb attack against the World Trade Center, in which six died and more than 1,000 were injured.

1994 The Taliban, a group of rural students, takes over much of Afghanistan.

1995 Bin Laden supports a failed plot to assassinate Egyptian president Hosni Mubarak, and backs the bombing of a military facility in Saudi Arabia, in which five U.S. military personnel are killed. The next year, he backs another bombing in Saudi Arabia, in which at least 19 U.S. servicemen are killed.

1996 The Taliban takes control of Kabul, the Afghan capital, and introduces an extremist version of Islam, which includes brutal punishments and harsh restrictions on women. Meanwhile, Sudan bows to U.S. pressure and asks bin Laden to leave the country. He takes refuge in Afghanistan.

June 1996 Bin Laden allegedly claims to have carried out attacks on U.S. soldiers in Somalia.

1997 Pakistan and Saudi Arabia recognize the Taliban as the country's rightful rulers. Most other countries, however, refuse to recognize the regime's legitimacy.

1998 U.S. embassies in Kenya and Tanzania are bombed, killing 224 people, including 12 Americans. The U.S. blames bin Laden, who allegedly operates from bases in Afghanistan. As a reprisal, the U.S. launches missiles against these bases. When Afghanistan refuses to hand over bin Laden, the United Nations in 1999 imposes an air embargo as well as financial sanctions.

2000 The USS Cole is bombed while in port in Yemen. Seventeen soldiers are killed. U.S. authorities suspect bin Laden.

2001 The U.N. adds more sanctions to those already in place. In March, the Taliban blows up enormous Buddha statues, saying the Koran forbids worship of idols. In May, the Taliban orders religious minorities to wear tags identifying themselves as non-Muslims, and Hindu women to veil themselves like other Afghan women.

Sept. 11, 2001 U.S. says that bin Laden and his terrorist group are leading suspects in the terror attacks on New York and Washington.

Oct. 7, 2001 The United States and the United Kingdom launch air strikes against the defiant Taliban government, headed by the one-eyed mujahedeen fighter Mullah Mohammed Omar, for refusing to turn over bin Laden and his al-Qaida commanders for prosecution as the terrorist mastermind behind the Sept. 11 attacks. A prolonged air and ground war against Taliban and al-Qaeda troops begins.

Dec. 7, 2001 Taliban forces abandon their last bastion, fleeing the southern city of Kandahar and leaving chaos in their wake. Taliban leader Omar is missing and will be arrested if found. In the mountainous east, fierce fighting and heavy bombing rages around a cave hide-out occupied by al-Qaida fighters loyal to bin Laden, who also goes missing.